Shingled solar cell module

ABSTRACT

A high efficiency configuration for a solar cell module comprises solar cells arranged in a shingled manner to form super cells, which may be arranged to efficiently use the area of the solar module, reduce series resistance, and increase module efficiency.

CROSS REFERENCE TO RELATED APPLICATIONS

This non-provisional patent application is a continuation of U.S. patentapplication Ser. No. 14/530,405 titled “Shingled Solar Cell Module” andfiled Oct. 31, 2014, and also claims priority to U.S. Provisional PatentApplication No. 62/003,223 titled “Shingled Solar Cell Module” filed May27, 2014, to U.S. Provisional Patent Application No. 62/036,215 titled“Shingled Solar Cell Module” filed Aug. 12, 2014, to U.S. ProvisionalPatent Application No. 62/042,615 titled “Shingled Solar Cell Module”filed Aug. 27, 2014, to U.S. Provisional Patent Application No.62/048,858 titled “Shingled Solar Cell Module” filed Sep. 11, 2014, toU.S. Provisional Patent Application No. 62/064,260 titled “ShingledSolar Cell Module” filed Oct. 15, 2014, to U.S. Provisional PatentApplication No. 62/064,834 titled “Shingled Solar Cell Module” filedOct. 16, 2014, and to U.S. Design patent application Ser. No. 29/506,415filed Oct. 15, 2014. Each of the patent applications in the precedinglist is incorporated herein by reference in its entirety for allpurposes.

FIELD OF THE INVENTION

The invention relates generally to solar cell modules in which the solarcells are arranged in a shingled manner.

BACKGROUND

Alternate sources of energy are needed to satisfy ever increasingworld-wide energy demands. Solar energy resources are sufficient in manygeographical regions to satisfy such demands, in part, by provision ofelectric power generated with solar (e.g., photovoltaic) cells.

SUMMARY

High efficiency arrangements of solar cells in a solar cell module, andmethods of making such solar modules, are disclosed herein.

In one aspect, a solar module comprises a series connected string ofN≧25 rectangular or substantially rectangular solar cells having onaverage a breakdown voltage greater than about 10 volts. The solar cellsare grouped into one or more super cells each of which comprises two ormore of the solar cells arranged in line with long sides of adjacentsolar cells overlapping and conductively bonded to each other with anelectrically and thermally conductive adhesive. No single solar cell orgroup of <N solar cells in the string of solar cells is individuallyelectrically connected in parallel with a bypass diode. Safe andreliable operation of the solar module is facilitated by effective heatconduction along the super cells through the bonded overlapping portionsof adjacent solar cells, which prevents or reduces formation of hotspots in reverse biased solar cells. The super cells may be encapsulatedin a thermoplastic olefin polymer sandwiched between glass front andback sheets, for example, further enhancing the robustness of the modulewith respect to thermal damage. In some variations, N is ≧30, ≧50, or≧100.

In another aspect, a super cell comprises a plurality of silicon solarcells each comprising rectangular or substantially rectangular front(sun side) and back surfaces with shapes defined by first and secondoppositely positioned parallel long sides and two oppositely positionedshort sides. Each solar cell comprises an electrically conductive frontsurface metallization pattern comprising at least one front surfacecontact pad positioned adjacent to the first long side, and anelectrically conductive back surface metallization pattern comprising atleast one back surface contact pad positioned adjacent the second longside. The silicon solar cells are arranged in line with first and secondlong sides of adjacent silicon solar cells overlapping and with frontsurface and back surface contact pads on adjacent silicon solar cellsoverlapping and conductively bonded to each other with a conductiveadhesive bonding material to electrically connect the silicon solarcells in series. The front surface metallization pattern of each siliconsolar cell comprises a barrier configured to substantially confine theconducive adhesive bonding material to the at least one front surfacecontact pads prior to curing of the conductive adhesive bonding materialduring manufacturing of the super cell.

In another aspect, a super cell comprises a plurality of silicon solarcells each comprising rectangular or substantially rectangular front(sun side) and back surfaces with shapes defined by first and secondoppositely positioned parallel long sides and two oppositely positionedshort sides. Each solar cell comprises an electrically conductive frontsurface metallization pattern comprising at least one front surfacecontact pad positioned adjacent to the first long side, and anelectrically conductive back surface metallization pattern comprising atleast one back surface contact pad positioned adjacent the second longside. The silicon solar cells are arranged in line with first and secondlong sides of adjacent silicon solar cells overlapping and with frontsurface and back surface contact pads on adjacent silicon solar cellsoverlapping and conductively bonded to each other with a conductiveadhesive bonding material to electrically connect the silicon solarcells in series. The back surface metallization pattern of each siliconsolar cell comprises a barrier configured to substantially confine theconducive adhesive bonding material to the at least one back surfacecontact pads prior to curing of the conductive adhesive bonding materialduring manufacturing of the super cell.

In another aspect, a method of making a string of solar cells comprisesdicing one or more pseudo square silicon wafers along a plurality oflines parallel to a long edge of each wafer to form a plurality ofrectangular silicon solar cells each having substantially the samelength along its long axis. The method also comprises arranging therectangular silicon solar cells in line with long sides of adjacentsolar cells overlapping and conductively bonded to each other toelectrically connect the solar cells in series. The plurality ofrectangular silicon solar cells comprises at least one rectangular solarcell having two chamfered corners corresponding to corners or toportions of corners of the pseudo square wafer, and one or morerectangular silicon solar cells each lacking chamfered corners. Thespacing between parallel lines along which the pseudo square wafer isdiced is selected to compensate for the chamfered corners by making thewidth perpendicular to the long axis of the rectangular silicon solarcells that comprise chamfered corners greater than the widthperpendicular to the long axis of the rectangular silicon solar cellsthat lack chamfered corners, so that each of the plurality ofrectangular silicon solar cells in the string of solar cells has a frontsurface of substantially the same area exposed to light in operation ofthe string of solar cells.

In another aspect, a super cell comprises a plurality of silicon solarcells arranged in line with end portions of adjacent solar cellsoverlapping and conductively bonded to each other to electricallyconnect the solar cells in series. At least one of the silicon solarcells has chamfered corners that correspond to corners or portions ofcorners of a pseudo square silicon wafer from which it was diced, atleast one of the silicon solar cells lacks chamfered corners, and eachof the silicon solar cells has a front surface of substantially the samearea exposed to light during operation of the string of solar cells.

In another aspect, a method of making two or more super cells comprisesdicing one or more pseudo square silicon wafers along a plurality oflines parallel to a long edge of each wafer to form a first plurality ofrectangular silicon solar cells comprising chamfered cornerscorresponding to corners or portions of corners of the pseudo squaresilicon wafers and a second plurality of rectangular silicon solar cellseach of a first length spanning a full width of the pseudo squaresilicon wafers and lacking chamfered corners. The method also comprisesremoving the chamfered corners from each of the first plurality ofrectangular silicon solar cells to form a third plurality of rectangularsilicon solar cells each of a second length shorter than the firstlength and lacking chamfered corners. The method further comprisesarranging the second plurality of rectangular silicon solar cells inline with long sides of adjacent rectangular silicon solar cellsoverlapping and conductively bonded to each other to electricallyconnect the second plurality of rectangular silicon solar cells inseries to form a solar cell string having a width equal to the firstlength, and arranging the third plurality of rectangular silicon solarcells in line with long sides of adjacent rectangular silicon solarcells overlapping and conductively bonded to each other to electricallyconnect the third plurality of rectangular silicon solar cells in seriesto form a solar cell string having a width equal to the second length.

In another aspect, a method of making two or more super cells comprisesdicing one or more pseudo square silicon wafers along a plurality oflines parallel to a long edge of each wafer to form a first plurality ofrectangular silicon solar cells comprising chamfered cornerscorresponding to corners or portions of corners of the pseudo squaresilicon wafers and a second plurality of rectangular silicon solar cellslacking chamfered corners, arranging the first plurality of rectangularsilicon solar cells in line with long sides of adjacent rectangularsilicon solar cells overlapping and conductively bonded to each other toelectrically connect the first plurality of rectangular silicon solarcells in series, and arranging the second plurality of rectangularsilicon solar cells in line with long sides of adjacent rectangularsilicon solar cells overlapping and conductively bonded to each other toelectrically connect the second plurality of rectangular silicon solarcells in series.

In another aspect, a super cell comprises a plurality of silicon solarcells arranged in line in a first direction with end portions ofadjacent silicon solar cells overlapping and conductively bonded to eachother to electrically connect the silicon solar cells in series, and anelongated flexible electrical interconnect with its long axis orientedparallel to a second direction perpendicular to the first direction,conductively bonded to a front or back surface of an end one of thesilicon solar cells at a plurality of discrete locations arranged alongthe second direction, running at least the full width of the end solarcell in the second direction, having a conductor thickness less than orequal to about 100 microns measured perpendicularly to the front or rearsurface of the end silicon solar cell, providing a resistance to currentflow in the second direction of less than or equal to about 0.012 Ohms,and configured to provide flexibility accommodating differentialexpansion in the second direction between the end silicon solar cell andthe interconnect for a temperature range of about −40° C. to about 85°C.

The flexible electrical interconnect may have a conductor thickness lessthan or equal to about 30 microns measured perpendicularly to the frontand rear surfaces of the end silicon solar cell, for example. Theflexible electrical interconnect may extend beyond the super cell in thesecond direction to provide for electrical interconnection to at least asecond super cell positioned parallel to and adjacent the super cell ina solar module. In addition, or alternatively, the flexible electricalinterconnect may extend beyond the super cell in the first direction toprovide for electrical interconnection to a second super cell positionedparallel to and in line with the super cell in a solar module.

In another aspect, a solar module comprises a plurality of super cellsarranged in two or more parallel rows spanning a width of the module toform a front surface of the module. Each super cell comprises aplurality of silicon solar cells arranged in line with end portions ofadjacent silicon solar cells overlapping and conductively bonded to eachother to electrically connect the silicon solar cells in series. Atleast an end of a first super cell adjacent an edge of the module in afirst row is electrically connected to an end of a second super celladjacent the same edge of the module in a second row via a flexibleelectrical interconnect that is bonded to the front surface of the firstsuper cell at a plurality of discrete locations with an electricallyconductive adhesive bonding material, runs parallel to the edge of themodule, and at least a portion of which folds around the end of thefirst super cell and is hidden from view from the front of the module.

In another aspect, a method of making a super cell comprises laserscribing one or more scribe lines on each of one or more silicon solarcells to define a plurality of rectangular regions on the silicon solarcells, applying an electrically conductive adhesive bonding material tothe one or more scribed silicon solar cells at one or more locationsadjacent a long side of each rectangular region, separating the siliconsolar cells along the scribe lines to provide a plurality of rectangularsilicon solar cells each comprising a portion of the electricallyconductive adhesive bonding material disposed on its front surfaceadjacent a long side, arranging the plurality of rectangular siliconsolar cells in line with long sides of adjacent rectangular siliconsolar cells overlapping in a shingled manner with a portion of theelectrically conductive adhesive bonding material disposed in between,and curing the electrically conductive bonding material, thereby bondingadjacent overlapping rectangular silicon solar cells to each other andelectrically connecting them in series.

In another aspect, a method of making a super cell comprises laserscribing one or more scribe lines on each of one or more silicon solarcells to define a plurality of rectangular regions on the silicon solarcells, applying an electrically conductive adhesive bonding material toportions of the top surfaces of the one or more silicon solar cells,applying a vacuum between the bottom surfaces of the one or more siliconsolar cells and a curved supporting surface to flex the one or moresilicon solar cells against the curved supporting surface and therebycleave the one or more silicon solar cells along the scribe lines toprovide a plurality of rectangular silicon solar cells each comprising aportion of the electrically conductive adhesive bonding materialdisposed on its front surface adjacent a long side, arranging theplurality of rectangular silicon solar cells in line with long sides ofadjacent rectangular silicon solar cells overlapping in a shingledmanner with a portion of the electrically conductive adhesive bondingmaterial disposed in between, and curing the electrically conductivebonding material, thereby bonding adjacent overlapping rectangularsilicon solar cells to each other and electrically connecting them inseries.

In another aspect, a method of making a solar module comprisesassembling a plurality of super cells, with each super cell comprising aplurality of rectangular silicon solar cells arranged in line with endportions on long sides of adjacent rectangular silicon solar cellsoverlapping in a shingled manner. The method also comprises curing anelectrically conductive bonding material disposed between theoverlapping end portions of adjacent rectangular silicon solar cells byapplying heat and pressure to the super cells, thereby bonding adjacentoverlapping rectangular silicon solar cells to each other andelectrically connecting them in series. The method also comprisesarranging and interconnecting the super cells in a desired solar moduleconfiguration in a stack of layers comprising an encapsulant, andapplying heat and pressure to the stack of layers to form a laminatedstructure.

Some variations of the method comprise curing or partially curing theelectrically conductive bonding material by applying heat and pressureto the super cells prior to applying heat and pressure to the stack oflayers to form the laminated structure, thereby forming cured orpartially cured super cells as an intermediate product before formingthe laminated structure. In some variations, as each additionalrectangular silicon solar cell is added to a super cell during assemblyof the super cell, the electrically conductive adhesive bonding materialbetween the newly added solar cell and its adjacent overlapping solarcell is cured or partially cured before any other rectangular siliconsolar cell is added to the super cell. Alternatively, some variationscomprise curing or partially curing all of the electrically conductivebonding material in a super cell in the same step.

If the super cells are formed as partially cured intermediate products,the method may comprise completing the curing of the electricallyconductive bonding material while applying heat and pressure to thestack of layers to form the laminated structure.

Some variations of the method comprise curing the electricallyconductive bonding material while applying heat and pressure to thestack of layers to form a laminated structure, without forming cured orpartially cured super cells as an intermediate product before formingthe laminated structure.

The method may comprise dicing one or more standard size silicon solarcells into rectangular shapes of smaller area to provide the rectangularsilicon solar cells. The electrically conductive adhesive bondingmaterial may be applied to the one or more silicon solar cells beforedicing the one or more silicon solar cells to provide the rectangularsilicon solar cells with pre-applied electrically conductive adhesivebonding material. Alternatively, the electrically conductive adhesivebonding material may be applied to the rectangular silicon solar cellsafter dicing the one or more silicon solar cells to provide therectangular silicon solar cells.

These and other embodiments, features and advantages of the presentinvention will become more apparent to those skilled in the art whentaken with reference to the following more detailed description of theinvention in conjunction with the accompanying drawings that are firstbriefly described.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a cross-sectional diagram of a string of series-connectedsolar cells arranged in a shingled manner with the ends of adjacentsolar cells overlapping to form a shingled super cell.

FIG. 2A shows a diagram of the front (sun side) surface and frontsurface metallization pattern of an example rectangular solar cell thatmay be used to form shingled super cells.

FIGS. 2B and 2C show diagrams of the front (sun side) surface and frontsurface metallization patterns of two example rectangular solar cellshaving rounded corners that may be used to form shingled super cells

FIGS. 2D and 2E show diagrams of the rear surfaces and example rearsurface metallization patterns for the solar cell shown in FIG. 2A.

FIGS. 2F and 2G show diagrams of the rear surfaces and example rearsurface metallization patterns for the solar cells shown in FIGS. 2B and2C, respectively.

FIG. 2H shows a diagram of the front (sun side) surface and frontsurface metallization pattern of another example rectangular solar cellthat may be used to form shingled super cells. The front surfacemetallization pattern comprises discrete contact pads each of which issurrounded by a barrier configured to prevent uncured conductiveadhesive bonding material deposited on its contact pad from flowing awayfrom the contact pad.

FIG. 2I shows a cross-sectional view of the solar cell of FIG. 2H andidentifies detail of the front surface metallization pattern shown inexpanded view in FIGS. 2J and 2K that includes a contact pad andportions of a barrier surrounding the contact pad.

FIG. 2J shows an expanded view of detail from FIG. 2I.

FIG. 2K shows an expanded view of detail from FIG. 2I with uncuredconductive adhesive bonding material substantially confined to thelocation of the discrete contact pad by the barrier.

FIG. 2L shows a diagram of the rear surface and an example rear surfacemetallization pattern for the solar cell of FIG. 2H. The rear surfacemetallization pattern comprises discrete contact pads each of which issurrounded by a barrier configured to prevent uncured conductiveadhesive bonding material deposited on its contact pad from flowing awayfrom the contact pad.

FIG. 2M shows a cross-sectional view of the solar cell of FIG. 2L andidentifies detail of the rear surface metallization pattern shown inexpanded view in FIG. 2N that includes a contact pad and portions of abarrier surrounding the contact pad.

FIG. 2N shows an expanded view of detail from FIG. 2M.

FIG. 2O shows another variation of a metallization pattern comprising abarrier configured to prevent uncured conductive adhesive bondingmaterial from flowing away from a contact pad. The barrier abuts oneside of the contact pad and is taller than the contact pad.

FIG. 2P shows another variation of the metallization pattern of FIG. 2O,with the barrier abutting at least two sides of the contact pad

FIG. 2Q shows a diagram of the rear surface and an example rear surfacemetallization pattern for another example rectangular solar cell. Therear surface metallization pattern comprises a continuous contact padrunning substantially the length of a long side of the solar cell alongan edge of the solar cell. The contact pad is surrounded by a barrierconfigured to prevent uncured conductive adhesive bonding materialdeposited on the contact pad from flowing away from the contact pad.

FIG. 2R shows a diagram of the front (sun side) surface and frontsurface metallization pattern of another example rectangular solar cellthat may be used to form shingled super cells. The front surfacemetallization pattern comprises discrete contact pads arranged in a rowalong an edge of the solar cell and a long thin conductor runningparallel to and inboard from the row of contact pads. The long thinconductor forms a barrier configured to prevent uncured conductiveadhesive bonding material deposited on its contact pads from flowingaway from the contact pads and onto active areas of the solar cell.

FIG. 3A shows a diagram illustrating an example method by which astandard size and shape pseudo square silicon solar cell may beseparated (e.g., cut, or broken) into rectangular solar cells of twodifferent lengths that may be used to form shingled super cells.

FIGS. 3B and 3C show diagrams illustrating another example method bywhich a pseudo square silicon solar cell may be separated intorectangular solar cells. FIG. 3B shows the front surface of the waferand an example front surface metallization pattern. FIG. 3C shows therear surface of the wafer and an example rear surface metallizationpattern.

FIGS. 3D and 3E show diagrams illustrating an example method by which asquare silicon solar cell may be separated into rectangular solar cells.FIG. 3D shows the front surface of the wafer and an example frontsurface metallization pattern. FIG. 3E shows the rear surface of thewafer and an example rear surface metallization pattern.

FIG. 4A shows a fragmentary view of the front surface of an examplerectangular super cell comprising rectangular solar cells as shown forexample in FIG. 2A arranged in a shingled manner as shown in FIG. 1.

FIGS. 4B and 4C show front and rear views, respectively, of an examplerectangular super cell comprising “chevron” rectangular solar cellshaving chamfered corners, as shown for example in FIG. 2B, arranged in ashingled manner as shown in FIG. 1.

FIG. 5A shows a diagram of an example rectangular solar modulecomprising a plurality of rectangular shingled super cells, with thelong side of each super cell having a length of approximately half thelength of the short sides of the module. Pairs of the super cells arearranged end-to-end to form rows with the long sides of the super cellsparallel to the short sides of the module.

FIG. 5B shows a diagram of another example rectangular solar modulecomprising a plurality of rectangular shingled super cells, with thelong side of each super cell having a length of approximately the lengthof the short sides of the module. The super cells are arranged withtheir long sides parallel to the short sides of the module.

FIG. 5C shows a diagram of another example rectangular solar modulecomprising a plurality of rectangular shingled super cells, with thelong side of each super cell having a length of approximately the lengthof the long side of the module. The super cells are arranged with theirlong sides parallel to the sides of the module.

FIG. 5D shows a diagram of an example rectangular solar modulecomprising a plurality of rectangular shingled super cells, with thelong side of each super cell having a length of approximately half thelength of the long sides of the module. Pairs of the super cells arearranged end-to-end to form rows with the long sides of the super cellsparallel to the long sides of the module.

FIG. 5E shows a diagram of another example rectangular solar modulesimilar in configuration to that of FIG. 5C, in which all of the solarcells from which the super cells are formed are chevron solar cellshaving chamfered corners corresponding to corners of pseudo-squarewafers from which the solar cells were separated.

FIG. 5F shows a diagram of another example rectangular solar modulesimilar in configuration to that of FIG. 5C, in which the solar cellsfrom which the super cells are formed comprise a mixture of chevron andrectangular solar cells arranged to reproduce the shapes of thepseudo-square wafers from which they were separated.

FIG. 5G shows a diagram of another example rectangular solar modulesimilar in configuration to that of FIG. 5E, except that adjacentchevron solar cells in a super cell are arranged as mirror images ofeach other so that their overlapping edges are of the same length.

FIG. 6 shows an example arrangement of three rows of super cellsinterconnected with flexible electrical interconnects to put the supercells within each row in series with each other, and to put the rows inparallel with each other. These may be three rows in the solar module ofFIG. 5D, for example.

FIG. 7 shows example flexible interconnects that may be used tointerconnect super cells in series or in parallel. Some of the examplesexhibit patterning that increase their flexibility (mechanicalcompliance) along their long axes, along their short axes, or alongtheir long axes and their short axes.

FIG. 8A shows Detail A from FIG. 5D: a cross-sectional view of theexample solar module of FIG. 5D showing cross-sectional details offlexible electrical interconnects bonded to the rear surface terminalcontacts of the rows of super cells.

FIG. 8B shows Detail C from FIG. 5D: a cross-sectional view of theexample solar module of FIG. 5D showing cross-sectional details offlexible electrical interconnects bonded to the front (sunny side)surface terminal contacts of the rows of super cells.

FIG. 8C shows Detail B from FIG. 5D: a cross-sectional view of theexample solar module of FIG. 5D showing cross-sectional details offlexible interconnects arranged to interconnect two super cells in a rowin series.

FIG. 8D-8G show additional examples of electrical interconnects bondedto a front terminal contact of a super cell at an end of a row of supercells, adjacent an edge of a solar module. The example interconnects areconfigured to have a small foot print on the front surface of themodule.

FIG. 9A shows a diagram of another example rectangular solar modulecomprising six rectangular shingled super cells, with the long side ofeach super cell having a length of approximately the length of the longside of the module. The super cells are arranged in six rows that areelectrically connected in parallel with each other and in parallel witha bypass diode disposed in a junction box on the rear surface of thesolar module. Electrical connections between the super cells and thebypass diode are made through ribbons embedded in the laminate structureof the module.

FIG. 9B shows a diagram of another example rectangular solar modulecomprising six rectangular shingled super cells, with the long side ofeach super cell having a length of approximately the length of the longside of the module. The super cells are arranged in six rows that areelectrically connected in parallel with each other and in parallel witha bypass diode disposed in a junction box on the rear surface and nearan edge of the solar module. A second junction box is located on therear surface near an opposite edge of the solar module. Electricalconnection between the super cells and the bypass diode are made throughan external cable between the junction boxes.

FIG. 9C shows an example glass-glass rectangular solar module comprisingsix rectangular shingled super cells, with the long side of each supercell having a length of approximately the length of the long side of themodule. The super cells are arranged in six rows that are electricallyconnected in parallel with each other. Two junction boxes are mounted onopposite edges of the module, maximizing the active area of the module.

FIG. 9D shows a side view of the solar module illustrated in FIG. 9C.

FIG. 9E shows another example solar module comprising six rectangularshingled super cells, with the long side of each super cell having alength of approximately the length of the long side of the module. Thesuper cells are arranged in six rows, with three pairs of rowsindividually connected to a power management device on the solar module.

FIG. 9F shows another example solar module comprising six rectangularshingled super cells, with the long side of each super cell having alength of approximately the length of the long side of the module. Thesuper cells are arranged in six rows, with each row individuallyconnected to a power management device on the solar module.

FIGS. 9G and 9H show other embodiments of architectures for module levelpower management using shingled super cells.

FIG. 10A shows an example schematic electrical circuit diagram for asolar module as illustrated in FIG. 5B.

FIGS. 10B-1 and 10B-2 show an example physical layout for variouselectrical interconnections for a solar module as illustrated in FIG. 5Bhaving the schematic circuit diagram of FIG. 10A.

FIG. 11A shows an example schematic electrical circuit diagram for asolar module as illustrated in FIG. 5A.

FIGS. 11B-1 and 11B-2 show an example physical layout for variouselectrical interconnections for a solar module as illustrated in FIG. 5Ahaving the schematic electrical circuit diagram of FIG. 11A.

FIGS. 11C-1 and 11C-2 show another example physical layout for variouselectrical interconnections for a solar module as illustrated in FIG. 5Ahaving the schematic electrical circuit diagram of FIG. 11A.

FIG. 12A shows another example schematic circuit diagram for a solarmodule as illustrated in FIG. 5A.

FIGS. 12B-1 and 12B-2 show an example physical layout for variouselectrical interconnections for a solar module as illustrated in FIG. 5Ahaving the schematic circuit diagram of FIG. 12A.

FIGS. 12C-1, 12C-2, and 12C-3 show another example physical layout forvarious electrical interconnections for a solar module as illustrated inFIG. 5A having the schematic circuit diagram of FIG. 12A.

FIG. 13A shows another example schematic circuit diagram for a solarmodule as illustrated in FIG. 5A.

FIG. 13B shows another example schematic circuit diagram for a solarmodule as illustrated in FIG. 5B.

FIGS. 13C-1 and 13C-2 show an example physical layout for variouselectrical interconnections for a solar module as illustrated in FIG. 5Ahaving the schematic circuit diagram of FIG. 13A. Slightly modified, thephysical layout of FIGS. 13C-1 and 13C-2 is suitable for a solar moduleas illustrated in FIG. 5B having the schematic circuit diagram of FIG.13B.

FIG. 14A shows a diagram of another example rectangular solar modulecomprising a plurality of rectangular shingled super cells, with thelong side of each super cell having a length of approximately half thelength of the short side of the module. Pairs of the super cells arearranged end-to-end to form rows with the long sides of the super cellsparallel to the short side of the module.

FIG. 14B shows an example schematic circuit diagram for a solar moduleas illustrated in FIG. 14A.

FIGS. 14C-1 and 14C-2 show an example physical layout for variouselectrical interconnections for a solar module as illustrated in FIG.14A having the schematic circuit diagram of FIG. 14B.

FIG. 15 shows another example physical layout for various electricalinterconnections for a solar module as illustrated in FIG. 5B having theschematic circuit diagram of FIG. 10A.

FIG. 16 shows an example arrangement of a smart switch interconnectingtwo solar modules in series.

FIG. 17 shows a flow chart for an example method of making a solarmodule with super cells.

FIG. 18 shows a flow chart for another example method of making a solarmodule with super cells.

FIGS. 19A-19D show example arrangements by which super cells may becured with heat and pressure.

FIGS. 20A-20C schematically illustrate an example apparatus that may beused to cleave scribed solar cells. The apparatus may be particularlyadvantageous when used to cleave scribed super cells to which conductiveadhesive bonding material has been applied.

FIG. 2I shows an example white back sheet “zebra striped” with darklines that may be used in solar modules comprising parallel rows ofsuper cells to reduce visual contrast between the super cells andportions of the back sheet visible from the front of the module.

FIG. 22A shows a plan view of a conventional module utilizingtraditional ribbon connections under hot spot conditions. FIG. 22B showsa plan view of a module utilizing thermal spreading according toembodiments, also under hot spot conditions.

FIGS. 23A-B show examples of super cell string layouts with chamferedcells.

FIGS. 24-25 show simplified cross-sectional views of arrays comprising aplurality of modules assembled in shingled configurations.

FIG. 26 shows a diagram of the rear (shaded) surface of a solar moduleillustrating an example electrical interconnection of the front (sunside) surface terminal electrical contacts of a shingled super cell to ajunction box on the rear side of the module.

FIG. 27 shows a diagram of the rear (shaded) surface of a solar moduleillustrating an example electrical interconnection of two or moreshingled super cells in parallel, with the front (sun side) surfaceterminal electrical contacts of the super cells connected to each otherand to a junction box on the rear side of the module.

FIG. 28 shows a diagram of the rear (shaded) surface of a solar moduleillustrating another example electrical interconnection of two or moreshingled super cells in parallel, with the front (sun side) surfaceterminal electrical contacts of the super cells connected to each otherand to a junction box on the rear side of the module.

FIG. 29 shows fragmentary cross-sectional and perspective diagrams oftwo super cells illustrating the use of a flexible interconnectsandwiched between overlapping ends of adjacent super cells toelectrically connect the super cells in series and to provide anelectrical connection to a junction box. FIG. 29A shows an enlarged viewof an area of interest in FIG. 29.

FIG. 30A shows an example super cell with electrical interconnectsbonded to its front and rear surface terminal contacts. FIG. 30B showstwo of the super cells of FIG. 30A interconnected in parallel.

DETAILED DESCRIPTION

The following detailed description should be read with reference to thedrawings, in which identical reference numbers refer to like elementsthroughout the different figures. The drawings, which are notnecessarily to scale, depict selective embodiments and are not intendedto limit the scope of the invention. The detailed descriptionillustrates by way of example, not by way of limitation, the principlesof the invention. This description will clearly enable one skilled inthe art to make and use the invention, and describes severalembodiments, adaptations, variations, alternatives and uses of theinvention, including what is presently believed to be the best mode ofcarrying out the invention.

As used in this specification and the appended claims, the singularforms “a,” “an,” and “the” include plural referents unless the contextclearly indicates otherwise. Also, the term “parallel” is intended tomean “parallel or substantially parallel” and to encompass minordeviations from parallel geometries rather than to require that anyparallel arrangements described herein be exactly parallel. The term“perpendicular” is intended to mean “perpendicular or substantiallyperpendicular” and to encompass minor deviations from perpendiculargeometries rather than to require that any perpendicular arrangementdescribed herein be exactly perpendicular. The term “square” is intendedto mean “square or substantially square” and to encompass minordeviations from square shapes, for example substantially square shapeshaving chamfered (e.g., rounded or otherwise truncated) corners. Theterm “rectangular” is intended to mean “rectangular or substantiallyrectangular” and to encompass minor deviations from rectangular shapes,for example substantially rectangular shapes having chamfered (e.g.,rounded or otherwise truncated) corners.

This specification discloses high-efficiency shingled arrangements ofsilicon solar cells in solar cell modules, as well as front and rearsurface metallization patterns and interconnects for solar cells thatmay be used in such arrangements. This specification also disclosesmethods for manufacturing such solar modules. The solar cell modules maybe advantageously employed under “one sun” (non-concentrating)illumination, and may have physical dimensions and electricalspecifications allowing them to be substituted for conventional siliconsolar cell modules.

FIG. 1 shows a cross-sectional view of a string of series-connectedsolar cells 10 arranged in a shingled manner with the ends of adjacentsolar cells overlapping and electrically connected to form a super cell100. Each solar cell 10 comprises a semiconductor diode structure andelectrical contacts to the semiconductor diode structure by whichelectric current generated in solar cell 10 when it is illuminated bylight may be provided to an external load.

In the examples described in this specification, each solar cell 10 is acrystalline silicon solar cell having front (sun side) surface and rear(shaded side) surface metallization patterns providing electricalcontact to opposite sides of an n-p junction, the front surfacemetallization pattern is disposed on a semiconductor layer of n-typeconductivity, and the rear surface metallization pattern is disposed ona semiconductor layer of p-type conductivity. However, any othersuitable solar cells employing any other suitable material system, diodestructure, physical dimensions, or electrical contact arrangement may beused instead of or in addition to solar cells 10 in the solar modulesdescribed in this specification. For example, the front (sun side)surface metallization pattern may be disposed on a semiconductor layerof p-type conductivity, and the rear (shaded side) surface metallizationpattern disposed on a semiconductor layer of n-type conductivity.

Referring again to FIG. 1, in super cell 100 adjacent solar cells 10 areconductively bonded to each other in the region in which they overlap byan electrically conducting bonding material that electrically connectsthe front surface metallization pattern of one solar cell to the rearsurface metallization pattern of the adjacent solar cell. Suitableelectrically conducting bonding materials may include, for example,electrically conducting adhesives and electrically conducting adhesivefilms and adhesive tapes, and conventional solders. Preferably, theelectrically conducting bonding material provides mechanical compliancein the bond between the adjacent solar cells that accommodates stressarising from mismatch between the coefficient of thermal expansion (CTE)of the electrically conducting bonding material and that of the solarcells (e.g., the CTE of silicon). To provide such mechanical compliance,in some variations the electrically conducting bonding material isselected to have a glass transition temperature of less than or equal toabout 0° C. To further reduce and accommodate stress parallel to theoverlapping edges of the solar cells arising from CTE mismatch, theelectrically conductive bonding material may optionally be applied onlyat discrete locations along the overlapping regions of the solar cellsrather than in a continuous line extending substantially the length ofthe edges of the solar cells

The thickness of the electrically conductive bond between adjacentoverlapping solar cells formed by the electrically conductive bondingmaterial, measured perpendicularly to the front and rear surfaces of thesolar cells, may be for example less than about 0.1 mm. Such a thin bondreduces resistive loss at the interconnection between cells, and alsopromotes flow of heat along the super cell from any hot spot in thesuper cell that might develop during operation. The thermal conductivityof the bond between solar cells may be, for example, ≧about 1.5Watts/(meter K).

FIG. 2A shows the front surface of an example rectangular solar cell 10that may be used in a super cell 100. Other shapes for solar cell 10 mayalso be used, as suitable. In the illustrated example the front surfacemetallization pattern of solar cell 10 includes a bus bar 15 positionedadjacent to the edge of one of the long sides of solar cell 10 andrunning parallel to the long sides for substantially the length of thelong sides, and fingers 20 attached perpendicularly to the bus bar andrunning parallel to each other and to the short sides of solar cell 10for substantially the length of the short sides.

In the example of FIG. 2A solar cell 10 has a length of about 156 mm, awidth of about 26 mm, and thus an aspect ratio (length of shortside/length of long side) of about 1:6. Six such solar cells may beprepared on a standard 156 mm×156 mm dimension silicon wafer, thenseparated (diced) to provide solar cells as illustrated. In othervariations, eight solar cells 10 having dimensions of about 19.5 mm×156mm, and thus an aspect ratio of about 1:8, may be prepared from astandard silicon wafer. More generally, solar cells 10 may have aspectratios of, for example, about 1:2 to about 1:20 and may be prepared fromstandard size wafers or from wafers of any other suitable dimensions.

FIG. 3A shows an example method by which a standard size and shapepseudo square silicon solar cell wafer 45 may be cut, broken, orotherwise divided to form rectangular solar cells as just described. Inthis example several full width rectangular solar cells 10L are cut fromthe central portion of the wafer, and in addition several shorterrectangular solar cells 10S are cut from end portions of the wafer andthe chamfered or rounded corners of the wafer are discarded. Solar cells10L may be used to form shingled super cells of one width, and solarcells 10S may be used to form shingled super cells of a narrower width.

Alternatively, the chamfered (e.g., rounded) corners may be retained onthe solar cells cut from end portions of the wafer. FIGS. 2B-2C show thefront surfaces of example “chevron” rectangular solar cells 10substantially similar to that of FIG. 2A, but having chamfered cornersretained from the wafer from which the solar cells were cut. In FIG. 2B,bus bar 15 is positioned adjacent to and runs parallel to the shorter ofthe two long sides for substantially the length of that side, andfurther extends at both ends at least partially around the chamferedcorners of the solar cell. In FIG. 2C, bus bar 15 is positioned adjacentto and runs parallel to the longer of the two long sides forsubstantially the length of that side. FIGS. 3B-3C show front and rearviews of a pseudo square wafer 45 that may be diced along the dashedlines shown in FIG. 3C to provide a plurality of solar cells 10 havingfront surface metallization patterns similar to that shown in FIG. 2A,and two chamfered solar cells 10 having front surface metallizationpatterns similar to that shown in FIG. 2B.

In the example front surface metallization pattern shown in FIG. 2B, thetwo end portions of bus bar 15 that extend around the chamfered cornersof the cell may each have a width that tapers (gradually narrows) withincreasing distance from the portion of the bus bar located adjacent thelong side of the cell. Similarly, in the example front surfacemetallization pattern shown in FIG. 3B, the two end portions of the thinconductor that interconnects discrete contact pads 15 extend around thechambered corners of the solar cell and taper with increasing distancefrom the long side of the solar cell along which the discrete contactpads are arranged. Such tapering is optional, but may advantageouslyreduce metal use and shading of the active region of the solar cellwithout significantly increasing resistive loss.

FIGS. 3D-3E show front and rear views of a perfect square wafer 47 thatmay be diced along the dashed lines shown in FIG. 3E to provide aplurality of solar cells 10 having front surface metallization patternssimilar to that shown in FIG. 2A.

Chamfered rectangular solar cells may be used to form super cellscomprising only chamfered solar cells. Additionally or alternatively,one or more such chamfered rectangular solar cells may be used incombination with one or more unchamfered rectangular solar cells (e.g.,FIG. 2A) to form a super cell. For example, the end solar cells of asuper cell may be chamfered solar cells, and the middle solar cellsunchamfered solar cells. If chamfered solar cells are used incombination with unchamfered solar cells in a super cell, or moregenerally in a solar module, it may be desirable to use dimensions forthe solar cells that result in the chamfered and unchamfered solar cellshaving the same front surface area exposed to light during operation ofthe solar cells. Matching the solar cell areas in this manner matchesthe current produced in the chamfered and unchamfered solar cells, whichimproves the performance of a series connected string that includes bothchamfered and unchamfered solar cells. The areas of chamfered andunchamfered solar cells cut from the same pseudo square wafer may bematched, for example, by adjusting locations of the lines along whichthe wafer is diced to make the chamfered solar cells slightly wider thanthe unchamfered solar cells in the direction perpendicular to their longaxes, to compensate for the missing corners on the chamfered solarcells.

A solar module may comprise only super cells formed exclusively fromunchamfered rectangular solar cells, or only super cells formed fromchamfered rectangular solar cells, or only super cells that includechamfered and unchamfered solar cells, or any combination of these threevariations of super cell.

In some instances portions of a standard size square or pseudo squaresolar cell wafer (e.g., wafer 45 or wafer 47) near the edges of thewafer may convert light to electricity with lower efficiency thanportions of the wafer located away from the edges. To improve theefficiency of the resulting rectangular solar cells, in some variationsone or more edges of the wafer are trimmed to remove the lowerefficiency portions before the wafer is diced. The portions trimmed fromthe edges of the wafer may have widths of about 1 mm to about 5 mm, forexample. Further, as shown in FIGS. 3B and 3D, the two end solar cells10 to be diced from a wafer may be oriented with their front surface busbars (or discrete contact pads) 15 along their outside edges and thusalong two of the edges of the wafer. Because in the super cellsdisclosed in this specification bus bars (or discrete contact pads) 15are typically overlapped by an adjacent solar cell, low light conversionefficiency along those two edges of the wafer typically does not affectperformance of the solar cells. Consequently, in some variations edgesof a square or pseudo square wafer oriented parallel to the short sidesof the rectangular solar cells are trimmed as just described, but edgesof the wafer oriented parallel to the long sides of rectangular solarcells are not. In other variations, one, two, three, or four edges of asquare wafer (e.g., wafer 47 in FIG. 3D) are trimmed as just described.In other variations, one, two, three, or four of the long edges of apseudo-square wafer are trimmed as just described.

Solar cells having long and narrow aspect ratios and areas less thanthat of a standard 156 mm×156 mm solar cell, as illustrated, may beadvantageously employed to reduce I²R resistive power losses in thesolar cell modules disclosed in this specification. In particular, thereduced area of solar cells 10 compared to standard size silicon solarcells decreases the current produced in the solar cell, directlyreducing resistive power loss in the solar cell and in a seriesconnected string of such solar cells. In addition, arranging suchrectangular solar cells in a super cell 100 so that current flowsthrough the super cell parallel to the short sides of the solar cellsmay reduce the distance that the current must flow through thesemiconductor material to reach fingers 20 in the front surfacemetallization pattern and reduce the required length of the fingers,which may also reduce resistive power loss.

As noted above, bonding overlapped solar cells 10 to each other in theiroverlapping region to electrically connect the solar cells in seriesreduces the length of the electrical connection between adjacent solarcells, compared to conventionally tabbed series-connected strings ofsolar cells. This also reduces resistive power loss.

Referring again to FIG. 2A, in the illustrated example the front surfacemetallization pattern on solar cell 10 comprises an optional bypassconductor 40 running parallel to and spaced apart from bus bar 15. (Sucha bypass conductor may also optionally be used in the metallizationpatterns shown in FIGS. 2B-2C, 3B, and 3D, and is also shown in FIG. 2Qin combination with discrete contact pads 15 rather than a continuousbus bar). Bypass conductor 40 interconnects fingers 20 to electricallybypass cracks that may form between bus bar 15 and bypass conductor 40.Such cracks, which may sever fingers 20 at locations near to bus bar 15,may otherwise isolate regions of solar cell 10 from bus bar 15. Thebypass conductor provides an alternative electrical path between suchsevered fingers and the bus bar. The illustrated example shows a bypassconductor 40 positioned parallel to bus bar 15, extending about the fulllength of the bus bar, and interconnecting every finger 20. Thisarrangement may be preferred but is not required. If present, the bypassconductor need not run parallel to the bus bar and need not extend thefull length of the bus bar. Further, a bypass conductor interconnects atleast two fingers, but need not interconnect all fingers. Two or moreshort bypass conductors may be used in place of a longer bypassconductor, for example. Any suitable arrangement of bypass conductorsmay be used. The use of such bypass conductors is described in greaterdetail in U.S. patent application Ser. No. 13/371,790, titled “SolarCell With Metallization Compensating For Or Preventing Cracking,” andfiled Feb. 13, 2012, which is incorporated herein by reference in itsentirety.

The example front surface metallization pattern of FIG. 2A also includesan optional end conductor 42 that interconnects fingers 20 at their farends, opposite from bus bar 15. (Such an end conductor may alsooptionally be used in the metallization patterns shown in FIGS. 2B-2C,3B, and 3D, and 2Q). The width of conductor 42 may be about the same asthat of a finger 20, for example. Conductor 42 interconnects fingers 20to electrically bypass cracks that may form between bypass conductor 40and conductor 42, and thereby provides a current path to bus bar 15 forregions of solar cell 10 that might otherwise be electrically isolatedby such cracks.

Although some of the illustrated examples show a front bus bar 15extending substantially the length of the long sides of solar cell 10with uniform width, this is not required. For example, as alluded toabove front bus bar 15 may be replaced by two or more front surfacediscrete contact pads 15 which may be arranged, for example, in linewith each other along a side of solar cell 10 as shown in FIGS. 2H, 2Q,and 3B for example. Such discrete contact pads may optionally beinterconnected by thinner conductors running between them, as shown forexample in the figures just mentioned. In such variations, the width ofthe contact pads measured perpendicularly to the long side of the solarcell may be for example about 2 to about 20 times that of the thinconductors interconnecting the contact pads. There may be a separate(e.g., small) contact pad for each finger in the front surfacemetallization pattern, or each contact pad may be connected to two ormore fingers. Front surface contact pads 15 may be square or have arectangular shape elongated parallel to the edge of the solar cell, forexample. Front surface contact pads 15 may have widths perpendicular tothe long side of the solar cell of about 1 mm to about 1.5 mm, forexample, and lengths parallel to the long side of the solar cell ofabout 1 mm to about 10 mm for example. The spacing between contact pads15 measured parallel to the long side of the solar cell may be about 3mm to about 30 mm, for example.

Alternatively, solar cell 10 may lack both a front bus bar 15 anddiscrete front contact pads 15 and include only fingers 20 in the frontsurface metallization pattern. In such variations, thecurrent-collecting functions that would otherwise be performed by afront bus bar 15 or contact pads 15 may instead be performed, orpartially performed, by the conductive material used to bond two solarcells 10 to each other in the overlapping configuration described above.

Solar cells lacking both a bus bar 15 and contact pads 15 may eitherinclude bypass conductor 40, or not include bypass conductor 40. If busbar 15 and contact pads 15 are absent, bypass conductor 40 may bearranged to bypass cracks that form between the bypass conductor and theportion of the front surface metallization pattern that is conductivelybonded to the overlapping solar cell.

The front surface metallization patterns, including bus bar or discretecontact pads 15, fingers 20, bypass conductor 40 (if present), and endconductor 42 (if present) may be formed, for example, from silver pasteconventionally used for such purposes and deposited, for example, byconventional screen printing methods. Alternatively, the front surfacemetallization patterns may be formed from electroplated copper. Anyother suitable materials and processes may be also used. In variationsin which the front surface metallization pattern is formed from silver,the use of discrete front surface contact pads 15 rather than acontinuous bus bar 15 along the edge of the cell reduces the amount ofsilver on the solar cell, which may advantageously reduce cost. Invariations in which the front surface metallization pattern is formedfrom copper or from another conductor less expensive than silver, acontinuous bus 15 may be employed without a cost disadvantage.

FIGS. 2D-2G, 3C, and 3E show example rear surface metallization patternsfor a solar cell. In these examples the rear surface metallizationpatterns include discrete rear surface contact pads 25 arranged alongone of the long edges of the rear surface of the solar cell and a metalcontact 30 covering substantially all of the remaining rear surface ofthe solar cell. In a shingled super cell, contact pads 25 are bonded forexample to a bus bar or to discrete contact pads arranged along the edgeof the upper surface of an adjacent overlapping solar cell toelectrically connect the two solar cells in series. For example, eachdiscrete rear surface contact pad 25 may be aligned with and bonded to acorresponding discrete front surface contact pad 15 on the front surfaceof the overlapping solar cell by electrically conductive bondingmaterial applied only to the discrete contact pads. Discrete contactpads 25 may be square (FIG. 2D) or have a rectangular shape elongatedparallel to the edge of the solar cell (FIGS. 2E-2G, 3C, 3E), forexample. Contact pads 25 may have widths perpendicular to the long sideof the solar cell of about 1 mm to about 5 mm, for example, and lengthsparallel to the long side of the solar cell of about 1 mm to about 10 mmfor example. The spacing between contact pads 25 measured parallel tothe long side of the solar cell may be about 3 mm to about 30 mm, forexample.

Contact 30 may be formed, for example, from aluminum and/orelectroplated copper. Formation of an aluminum back contact 30 typicallyprovides a back surface field that reduces back surface recombination inthe solar cell and thereby improves solar cell efficiency. If contact 30is formed from copper rather than aluminum, contact 30 may be used incombination with another passivation scheme (e.g., aluminum oxide) tosimilarly reduce back surface recombination. Discrete contact pads 25may be formed, for example, from silver paste. The use of discretesilver contact pads 25 rather than a continuous silver contact pad alongthe edge of the cell reduces the amount of silver in the rear surfacemetallization pattern, which may advantageously reduce cost.

Further, if the solar cells rely on a back surface field provided byformation of an aluminum contact to reduce back surface recombination,the use of discrete silver contacts rather than a continuous silvercontact may improve solar cell efficiency. This is because the silverrear surface contacts do not provide a back surface field and thereforetend to promote carrier recombination and produce dead (inactive)volumes in the solar cells above the silver contacts. In conventionallyribbon-tabbed solar cell strings those dead volumes are typically shadedby ribbons and/or bus bars on the front surface of the solar cell, andthus do not result in any extra loss of efficiency. In the solar cellsand super cells disclosed herein, however, the volume of the solar cellabove rear surface silver contact pads 25 is typically unshaded by anyfront surface metallization, and any dead volumes resulting from use ofsilver rear surface metallization reduce the efficiency of the cell. Theuse of discrete silver contact pads 25 rather than a continuous silvercontact pad along the edge of the rear surface of the solar cell thusreduces the volume of any corresponding dead zones and increases theefficiency of the solar cell.

In variations not relying on a back surface field to reduce back surfacerecombination, the rear surface metallization pattern may employ acontinuous bus bar 25 extending the length of the solar cell rather thandiscrete contact pads 25, as shown for example in FIG. 2R. Such a busbar 25 may be formed for example, from tin or silver.

Other variations of the rear surface metallization patterns may employdiscrete tin contact pads 25. Variations of the rear surfacemetallization patterns may employ finger contacts similar to those shownin the front surface metallization patterns of FIGS. 2A-2C and may lackcontact pads and a bus bar.

Although the particular example solar cells shown in the figures aredescribed as having particular combinations of front and rear surfacemetallization patterns, more generally any suitable combination of frontand rear surface metallization patterns may be used. For example, onesuitable combination may employ a silver front surface metallizationpattern comprising discrete contact pads 15, fingers 20, and an optionalbypass conductor 40, and a rear surface metallization pattern comprisingan aluminum contact 30 and discrete silver contact pads 25. Anothersuitable combination may employ a copper front surface metallizationpattern comprising a continuous bus bar 15, fingers 20, and an optionalbypass conductor 40, and a rear surface metallization pattern comprisinga continuous bus bar 25 and a copper contact 30.

In the super cell manufacturing process (described in more detail below)the electrically conductive bonding material used to bond adjacentoverlapping solar cells in a super cell may be dispensed only onto(discrete or continuous) contact pads at the edge of the front or rearsurface of the solar cell, and not onto the surrounding portions of thesolar cell. This reduces use of material and, as described above, mayreduce or accommodate stress arising from CTE mismatch between theelectrically conductive bonding material and the solar cell. However,during or after deposition and prior to curing, portions of theelectrically conductive bonding material may tend to spread beyond thecontact pads and onto surrounding portions of the solar cell. Forexample, a binding resin portion of the electrically conductive bondingmaterial may be drawn off of a contact pad onto textured or porousadjacent portions of the solar cell surface by capillary forces. Inaddition, during the deposition process some of the conductive bondingmaterial may miss the contact pad and instead be deposited on adjacentportions of the solar cell surface, and possibly spread from there. Thisspreading and/or inaccurate deposition of the conductive bondingmaterial may weaken the bond between the overlapping solar cells and maydamage the portions of the solar cell onto which the conductive bondingmaterial has spread or been mistakenly deposited. Such spreading of theelectrically conductive bonding material may be reduced or prevented,for example, with a metallization pattern that forms a dam or barriernear or around each contact pad to retain the electrically conductivebonding material substantially in place.

As shown in FIGS. 2H-2K, for example, the front surface metallizationpattern may comprise discrete contact pads 15, fingers 20, and barriers17, with each barrier 17 surrounding a corresponding contact pad 15 andacting as a dam to form a moat between the contact pad and the barrier.Portions 19 of uncured conductive adhesive bonding material 18 that flowoff of the contact pads, or that miss the contact pads when dispensedonto the solar cell, may be confined by barriers 17 to the moats. Thisprevents the conductive adhesive bonding material from spreading furtherfrom the contact pads onto surrounding portions of the cell. Barriers 17may be formed from the same material as fingers 20 and contact pads 15(e.g., silver), for example, may have heights of about 10 microns toabout 40 microns, for example, and may have widths of about 30 micronsto about 100 microns, for example. The moat formed between a barrier 17and a contact pad 15 may have a width of about 100 microns to about 2mm, for example. Although the illustrated examples comprise only asingle barrier 17 around each front contact pad 15, in other variationstwo or more such barriers may be positioned concentrically, for example,around each contact pad. A front surface contact pad and its one or moresurrounding barriers may form a shape similar to a “bulls-eye” target,for example. As shown in FIG. 2H, for example, barriers 17 mayinterconnect with fingers 20 and with the thin conductorsinterconnecting contact pads 15.

Similarly, as shown in FIGS. 2L-2N, for example, the rear surfacemetallization pattern may comprise (e.g., silver) discrete rear contactpads 25, (e.g., aluminum) contact 30 covering substantially all of theremaining rear surface of the solar cell, and (e.g., silver) barriers27, with each barrier 27 surrounding a corresponding rear contact pad 25and acting as a dam to form a moat between the contact pad and thebarrier. A portion of contact 30 may fill the moat, as illustrated.Portions of uncured conductive adhesive bonding material that flow offof contact pads 25, or that miss the contact pads when dispensed ontothe solar cell, may be confined by barriers 27 to the moats. Thisprevents the conductive adhesive bonding material from spreading furtherfrom the contact pads onto surrounding portions of the cell. Barriers 27may have heights of about 10 microns to about 40 microns, for example,and may have widths of about 50 microns to about 500 microns, forexample. The moat formed between a barrier 27 and a contact pad 25 mayhave a width of about 100 microns to about 2 mm, for example. Althoughthe illustrated examples comprise only a single barrier 27 around eachrear surface contact pad 25, in other variations two or more suchbarriers may be positioned concentrically, for example, around eachcontact pad. A rear surface contact pad and its one or more surroundingbarriers may form a shape similar to a “bulls-eye” target, for example.

A continuous bus bar or contact pad running substantially the length ofthe edge of a solar cell may also be surrounded by a barrier thatprevents spreading of the conductive adhesive bonding material. Forexample, FIG. 2Q shows such a barrier 27 surrounding a rear surface busbar 25. A front surface bus bar (e.g., bus bar 15 in FIG. 2A) may besimilarly surrounded by a barrier. Similarly, a row of front or rearsurface contact pads may be surrounded as a group by such a barrier,rather than individually surrounded by separate barriers.

Rather than surrounding a bus bar or one or more contact pads as justdescribed, a feature of the front or rear surface metallization patternmay form a barrier running substantially the length of the solar cellparallel to the overlapped edge of the solar cell, with the bus bar orcontact pads positioned between the barrier and the edge of the solarcell. Such a barrier may do double duty as a bypass conductor (describedabove). For example, in FIG. 2R bypass conductor 40 provides a barrierthat tends to prevent uncured conductive adhesive bonding material oncontact pads 15 from spreading onto the active area of the front surfaceof the solar cell. A similar arrangement may be used for rear surfacemetallization patterns.

Barriers to the spread of conductive adhesive bonding material may bespaced apart from contact pads or bus bars to form a moat as justdescribed, but this is not required. Such barriers may instead abut acontact pad or bus bar, as shown in FIG. 2O or 2P for example. In suchvariations the barrier is preferably taller than the contact pad or busbar, to retain the uncured conductive adhesive bonding material on thecontact pad or bus bar. Although FIGS. 2O and 2P show portions of afront surface metallization pattern, similar arrangements may be usedfor rear surface metallization patterns.

Barriers to the spread of conductive adhesive bonding material and/ormoats between such barriers and contact pads or bus bars, and anyconductive adhesive bonding material that has spread into such moats,may optionally lie within the region of the solar cell surfaceoverlapped by the adjacent solar cell in the super cell, and thus behidden from view and shielded from exposure to solar radiation.

Alternatively or in addition to the use of barriers as just described,the electrically conductive bonding material may be deposited using amask or by any other suitable method (e.g., screen printing) allowingaccurate deposition and thus requiring reduced amounts of electricallyconductive bonding material that are less likely to spread beyond thecontact pads or miss the contact pads during deposition.

More generally, solar cells 10 may employ any suitable front and rearsurface metallization patterns.

FIG. 4A shows a portion of the front surface of an example rectangularsuper cell 100 comprising solar cells 10 as shown in FIG. 2A arranged ina shingled manner as shown in FIG. 1. As a result of the shinglinggeometry, there is no physical gap between pairs of solar cells 10. Inaddition, although bus bar 15 of the solar cell 10 at one end of supercell 100 is visible, the bus bars (or front surface contact pads) of theother solar cells are hidden beneath overlapping portions of adjacentsolar cells. As a consequence, super cell 100 efficiently uses the areait takes up in a solar module. In particular, a larger portion of thatarea is available to produce electricity than is the case forconventionally tabbed solar cell arrangements and solar cellarrangements including numerous visible bus bars on the illuminatedsurface of the solar cells. FIGS. 4B-4C show front and rear views,respectively, of another example super cell 100 comprising primarilychamfered chevron rectangular silicon solar cells but otherwise similarto that of FIG. 4A.

In the example illustrated in FIG. 4A, bypass conductors 40 are hiddenby overlapping portions of adjacent cells. Alternatively, solar cellscomprising bypass conductors 40 may be overlapped similarly to as shownin FIG. 4A without covering the bypass conductors.

The exposed front surface bus bar 15 at one end of super cell 100 andthe rear surface metallization of the solar cell at the other end ofsuper cell 100 provide negative and positive (terminal) end contacts forthe super cell that may be used to electrically connect super cell 100to other super cells and/or to other electrical components as desired.

Adjacent solar cells in super cell 100 may overlap by any suitableamount, for example by about 1 millimeter (mm) to about 5 mm.

As shown in FIGS. 5A-5G, for example, shingled super cells as justdescribed may efficiently fill the area of a solar module. Such solarmodules may be square or rectangular, for example. Rectangular solarmodules as illustrated in FIGS. 5A-5G may have shorts sides having alength, for example, of about 1 meter and long sides having a length,for example, of about 1.5 to about 2.0 meters. Any other suitable shapesand dimensions for the solar modules may also be used. Any suitablearrangement of super cells in a solar module may be used.

In a square or rectangular solar module, the super cells are typicallyarranged in rows parallel to the short or long sides of the solarmodule. Each row may include one, two, or more super cells arrangedend-to-end. A super cell 100 forming part of such a solar module mayinclude any suitable number of solar cells 10 and be of any suitablelength. In some variations super cells 100 each have a lengthapproximately equal to the length of the short sides of a rectangularsolar module of which they are a part. In other variations super cells100 each have a length approximately equal to one half the length of theshort sides of a rectangular solar module of which they are a part. Inother variations super cells 100 each have a length approximately equalto the length of the long sides of a rectangular solar module of whichthey are a part. In other variations super cells 100 each have a lengthapproximately equal to one half the length of the long sides of arectangular solar module of which they are a part. The number of solarcells required to make super cells of these lengths depends of course onthe dimensions of the solar module, the dimensions of the solar cells,and the amount by which adjacent solar cells overlap. Any other suitablelengths for super cells may also be used.

In variations in which a super cell 100 has a length approximately equalto the length of the short sides of a rectangular solar module, thesuper cell may include, for example, 56 rectangular solar cells havingdimensions of about 19.5 millimeters (mm) by about 156 mm, with adjacentsolar cells overlapped by about 3 mm. Eight such rectangular solar cellsmay be separated from a conventional square or pseudo square 156 mmwafer. Alternatively such a super cell may include, for example, 38rectangular solar cells having dimensions of about 26 mm by about 156mm, with adjacent solar cells overlapped by about 2 mm. Six suchrectangular solar cells may be separated from a conventional square orpseudo square 156 mm wafer. In variations in which a super cell 100 hasa length approximately equal to half the length of the short sides of arectangular solar module, the super cell may include, for example, 28rectangular solar cells having dimensions of about 19.5 millimeters (mm)by about 156 mm, with adjacent solar cells overlapped by about 3 mm.Alternatively, such a super cell may include, for example, 19rectangular solar cells having dimensions of about 26 mm by about 156mm, with adjacent solar cells overlapped by about 2 mm.

In variations in which a super cell 100 has a length approximately equalto the length of the long sides of a rectangular solar module, the supercell may include, for example, 72 rectangular solar cells havingdimensions of about 26 mm by about 156 mm, with adjacent solar cellsoverlapped by about 2 mm. In variations in which a super cell 100 has alength approximately equal to one half the length of the long sides of arectangular solar module, the super cell may include, for example, 36rectangular solar cells having dimensions of about 26 mm by about 156mm, with adjacent solar cells overlapped by about 2 mm.

FIG. 5A shows an example rectangular solar module 200 comprising twentyrectangular super cells 100, each of which has a length approximatelyequal to one half the length of the short sides of the solar module. Thesuper cells are arranged end-to-end in pairs to form ten rows of supercells, with the rows and the long sides of the super cells orientedparallel to the short sides of the solar module. In other variations,each row of super cells may include three or more super cells. Also, asimilarly configured solar module may include more or fewer rows ofsuper cells than shown in this example. (FIG. 14A for example shows asolar module comprising twenty-four rectangular super cells arranged intwelve rows of two super cells each).

Gap 210 shown in FIG. 5A facilitates making electrical contact to frontsurface end contacts (e.g., exposed bus bars or discrete contacts 15) ofsuper cells 100 along the center line of the solar module, in variationsin which the super cells in each row are arranged so that at least oneof them has a front surface end contact on the end of the super celladjacent to the other super cell in the row. For example, the two supercells in a row may be arranged with one super cell having its frontsurface terminal contact along the center line of the solar module andthe other super cell having its rear surface terminal contact along thecenter line of the solar module. In such an arrangement the two supercells in a row may be electrically connected in series by aninterconnect arranged along the center line of the solar module andbonded to the front surface terminal contact of one super cell and tothe rear surface terminal contact of the other super cell. (See e.g.FIG. 8C discussed below). In variations in which each row of super cellsincludes three or more super cells, additional gaps between super cellsmay be present and may similarly facilitate making electrical contact tofront surface end contacts that are located away from the sides of thesolar module.

FIG. 5B shows an example rectangular solar module 300 comprising tenrectangular super cells 100, each of which has a length approximatelyequal to the length of the short sides of the solar module. The supercells are arranged as ten parallel rows with their long sides orientedparallel to the short sides of the module. A similarly configured solarmodule may include more or fewer rows of such side-length super cellsthan shown in this example.

FIG. 5B also shows what solar module 200 of FIG. 5A looks like whenthere are no gaps between adjacent super cells in the rows of supercells in solar module 200. Gap 210 of FIG. 5A can be eliminated, forexample, by arranging the super cells so that both super cells in eachrow have their back surface end contacts along the center line of themodule. In this case the super cells may be arranged nearly abuttingeach other with little or no extra gap between them because no access tothe front surface of the super cell is required along the center of themodule. Alternatively, two super cells 100 in a row may be arranged withone having its front surface end contact along a side of the module andits rear surface end contact along the center line of the module, theother having its front surface end contact along the center line of themodule and its rear surface end contact along the opposite side of themodule, and the adjacent ends of the super cells overlapping. A flexibleinterconnect may be sandwiched between the overlapping ends of the supercells, without shading any portion of the front surface of the solarmodule, to provide an electrical connection to the front surface endcontact of one of the super cells and the rear surface end contact ofthe other super cell. For rows containing three or more super cellsthese two approaches may be used in combination.

The super cells and rows of super cells shown in FIGS. 5A-5B may beinterconnected by any suitable combination of series and parallelelectrical connections, for example as described further below withrespect to FIGS. 10A-15. The interconnections between super cells may bemade, for example, using flexible interconnects similarly to asdescribed below with respect to FIGS. 5C-5G and subsequent figures.

FIG. 5C shows an example rectangular solar module 350 comprising sixrectangular super cells 100, each of which has a length approximatelyequal to the length of the long sides of the solar module. The supercells are arranged as six parallel rows with their long sides orientedparallel to the long sides of the module. A similarly configured solarmodule may include more or fewer rows of such side-length super cellsthan shown in this example. Each super cell in this example (and inseveral of the following examples) comprises 72 rectangular solar cellseach having a width approximately equal to ⅙ the width of a 156 mmsquare or pseudo square wafer. Any other suitable number of rectangularsolar cells of any other suitable dimensions may also be used. In thisexample the front surface terminal contacts of the super cells areelectrically connected to each other with flexible interconnects 400positioned adjacent to and running parallel to the edge of one shortside of the module. The rear surface terminal contacts of the supercells are similarly connected to each other by flexible interconnectspositioned adjacent to and running parallel to the edge of the othershort side, behind the solar module. The rear surface interconnects arehidden from view in FIG. 5C. This arrangement electrically connects thesix module-length super cells in parallel. Details of the flexibleinterconnects and their arrangement in this and other solar moduleconfigurations are discussed in more detail below with respect to FIGS.6-8G.

FIG. 5D shows an example rectangular solar module 360 comprising twelverectangular super cells 100, each of which has a length approximatelyequal to one half the length of the long sides of the solar module. Thesuper cells are arranged end-to-end in pairs to form six rows of supercells, with the rows and the long sides of the super cells orientedparallel to the long sides of the solar module. In other variations,each row of super cells may include three or more super cells. Also, asimilarly configured solar module may include more or fewer rows ofsuper cells than shown in this example. Each super cell in this example(and in several of the following examples) comprises 36 rectangularsolar cells each having a width approximately equal to ⅙ the width of a156 mm square or pseudo square wafer. Any other suitable number ofrectangular solar cells of any other suitable dimensions may also beused. Gap 410 facilitates making electrical contact to front surface endcontacts of super cells 100 along the center line of the solar module.In this example, flexible interconnects 400 positioned adjacent to andrunning parallel to the edge of one short side of the moduleelectrically interconnect the front surface terminal contacts of six ofthe super cells. Similarly, flexible interconnects positioned adjacentto and running parallel to the edge of the other short side of themodule behind the module electrically connect the rear surface terminalcontacts of the other six super cells. Flexible interconnects (not shownin this figure) positioned along gap 410 interconnect each pair of supercells in a row in series and, optionally, extend laterally tointerconnect adjacent rows in parallel. This arrangement electricallyconnects the six rows of super cells in parallel. Optionally, in a firstgroup of super cells the first super cell in each row is electricallyconnected in parallel with the first super cell in each of the otherrows, in a second group of super cells the second super cell iselectrically connected in parallel with the second super cell in each ofthe other rows, and the two groups of super cells are electricallyconnect in series. The later arrangement allows each of the two groupsof super cells to be individually put in parallel with a bypass diode.

Detail A in FIG. 5D identifies the location of a cross-sectional viewshown in FIG. 8A of the interconnection of the rear surface terminalcontacts of super cells along the edge of one short side of the module.Detail B similarly identifies the location of a cross-sectional viewshown in FIG. 8B of the interconnection of the front surface terminalcontacts of super cells along the edge of the other short side of themodule. Detail C identifies the location of a cross-sectional view shownin FIG. 8C of series interconnection of the super cells within a rowalong gap 410.

FIG. 5E shows an example rectangular solar module configured similarlyto that of FIG. 5C, except that in this example all of the solar cellsfrom which the super cells are formed are chevron solar cells havingchamfered corners corresponding to corners of pseudo-square wafers fromwhich the solar cells were separated.

FIG. 5F shows another example rectangular solar module configuredsimilarly to that of FIG. 5C, except that in this example the solarcells from which the super cells are formed comprise a mixture ofchevron and rectangular solar cells arranged to reproduce the shapes ofthe pseudo-square wafers from which they were separated. In the exampleof FIG. 5F, the chevron solar cells may be wider perpendicular to theirlong axes than are the rectangular solar cells to compensate for themissing corners on the chevron cells, so that the chevron solar cellsand the rectangular solar cells have the same active area exposed tosolar radiation during operation of the module and therefore matchedcurrent.

FIG. 5G shows another example rectangular solar module configuredsimilarly to that of FIG. 5E (i.e., including only chevron solar cells)except that in the solar module of FIG. 5G adjacent chevron solar cellsin a super cell are arranged as mirror images of each other so thattheir overlapping edges are of the same length. This maximizes thelength of each overlapping joint, and thereby facilitates heat flowthrough the super cell.

Other configurations of rectangular solar modules may include one ormore rows of super cells formed only from rectangular (non-chamfered)solar cells, and one or more rows of super cells formed only fromchamfered solar cells. For example, a rectangular solar module may beconfigured similarly to that of FIG. 5C, except having the two outerrows of super cells each replaced by a row of super cells formed onlyfrom chamfered solar cells. The chamfered solar cells in those rows maybe arranged in mirror image pairs as shown in FIG. 5G, for example.

In the example solar modules shown in FIGS. 5C-5G, the electric currentalong each row of super cells is about ⅙ of that in a conventional solarmodule of the same area because the rectangular solar cells from whichthe super cells are formed has an active area of about ⅙ that of aconventionally sized solar cell. Because in these examples the six rowsof super cells are electrically connected in parallel, however, theexample solar modules may generate a total electric current equal tothat generated by a conventional solar module of the same area. Thisfacilitates substation of the example solar modules of FIGS. 5C-5G (andother examples described below) for conventional solar modules.

FIG. 6 shows in more detail than FIGS. 5C-5G an example arrangement ofthree rows of super cells interconnected with flexible electricalinterconnects to put the super cells within each row in series with eachother, and to put the rows in parallel with each other. These may bethree rows in the solar module of FIG. 5D, for example. In the exampleof FIG. 6, each super cell 100 has a flexible interconnect 400conductively bonded to its front surface terminal contact, and anotherflexible interconnect conductively bonded to its rear surface terminalcontact. The two super cells within each row are electrically connectedin series by a shared flexible interconnect conductively bonded to thefront surface terminal contact of one super cell and to the rear surfaceterminal contact of the other super cell. Each flexible interconnect ispositioned adjacent to and runs parallel to an end of a super cell towhich it is bonded, and may extend laterally beyond the super cell to beconductively bonded to a flexible interconnect on a super cell in anadjacent row, electrically connecting the adjacent rows in parallel.Dotted lines in FIG. 6 depict portions of the flexible interconnectsthat are hidden from view by overlying portions of the super cells, orportions of the super cells that are hidden from view by overlyingportions of the flexible interconnects.

Flexible interconnects 400 may be conductively bonded to the super cellswith, for example, a mechanically compliant electrically conductivebonding material as described above for use in bonding overlapped solarcells. Optionally, the electrically conductive bonding material may belocated only at discrete positions along the edges of the super cellrather than in a continuous line extending substantially the length ofthe edge of the super cell, to reduce or accommodate stress parallel tothe edges of the super cell arising from mismatch between thecoefficient of thermal expansion of the electrically conductive bondingmaterial or the interconnects and that of the super cell.

Flexible interconnects 400 may be formed from or comprise thin coppersheets, for example. Flexible interconnects 400 may be optionallypatterned or otherwise configured to increase their mechanicalcompliance (flexibility) both perpendicular to and parallel to the edgesof the super cells to reduce or accommodate stress perpendicular andparallel to the edges of the super cells arising from mismatch betweenthe CTE of the interconnect and that of the super cells. Such patterningmay include, for example, slits, slots, or holes. Conductive portions ofinterconnects 400 may have a thickness of, for example, less than about100 microns, less than about 50 microns, less than about 30 microns, orless than about 25 microns to increase the flexibility of theinterconnects. The mechanical compliance of the flexible interconnect,and its bonds to the super cells, should be sufficient for theinterconnected super cells to survive stress arising from CTE mismatchduring the lamination process described in more detail below withrespect to methods of manufacturing shingled solar cell modules, and tosurvive stress arising from CTE mismatch during temperature cyclingtesting between about −40° C. and about 85° C.

Preferably, flexible interconnects 400 exhibit a resistance to currentflow parallel to the ends of the super cells to which they are bonded ofless than or equal to about 0.015 Ohms, less than or equal to about0.012 Ohms, or less than or equal to about 0.01 Ohms.

FIG. 7 shows several example configurations, designated by referencenumerals 400A-400T, that may be suitable for flexible interconnect 400,

As shown in the cross-sectional views of FIGS. 8A-8C, for example, thesolar modules described in this specification typically comprise alaminate structure with super cells and one or more encapsulantmaterials 410 sandwiched between a transparent front sheet 420 and aback sheet 430. The transparent front sheet may be glass, for example.Optionally, the back sheet may also be transparent, which may allowbifacial operation of the solar module. The back sheet may be a polymersheet, for example. Alternatively, the solar module may be a glass-glassmodule with both the front and back sheets glass.

The cross-sectional view of FIG. 8A (detail A from FIG. 5D) shows anexample of a flexible interconnect 400 conductively bonded to a rearsurface terminal contact of a super cell near the edge of the solarmodule and extending inward beneath the super cell, hidden from viewfrom the front of the solar module. An extra strip of encapsulant may bedisposed between interconnect 400 and the rear surface of the supercell, as illustrated.

The cross-sectional view of FIG. 8B (Detail B from FIG. 5B) shows anexample of a flexible interconnect 400 conductively bonded to a frontsurface terminal contact of a super cell.

The cross-sectional view of FIG. 8C (Detail C from FIG. 5B) shows anexample of a shared flexible interconnect 400 conductively bonded to thefront surface terminal contact of one super cell and to the rear surfaceterminal contact of the other super cell to electrically connect the twosuper cells in series.

Flexible interconnects electrically connected to the front surfaceterminal contact of a super cell may be configured or arranged to occupyonly a narrow width of the front surface of the solar module, which mayfor example be located adjacent an edge of the solar module. The regionof the front surface of the module occupied by such interconnects mayhave a narrow width perpendicular to the edge of the super cell of, forexample, ≦about 10 mm, ≦about 5 mm, or ≦about 3 mm. In the arrangementshown in FIG. 8B, for example, flexible interconnect 400 may beconfigured to extend beyond the end of the super cell by no more thansuch a distance. FIGS. 8D-8G show additional examples of arrangements bywhich a flexible interconnect electrically connected to a front surfaceterminal contact of a super cell may occupy only a narrow width of thefront surface of the module. Such arrangements facilitate efficient useof the front surface area of the module to produce electricity.

FIG. 8D shows a flexible interconnect 400 that is conductively bonded toa terminal front surface contact of a super cell and folded around theedge of the super cell to the rear of the super cell. An insulating film435, which may be pre-coated on flexible interconnect 400, may bedisposed between flexible interconnect 400 and the rear surface of thesuper cell.

FIG. 8E shows a flexible interconnect 400 comprising a thin narrowribbon 440 that is conductively bonded to a terminal front surfacecontact of a super cell and also to a thin wide ribbon 445 that extendsbehind the rear surface of the super cell. An insulating film 435, whichmay be pre-coated on ribbon 445, may be disposed between ribbon 445 andthe rear surface of the super cell.

FIG. 8F shows a flexible interconnect 400 bonded to a terminal frontsurface contact of a super cell and rolled and pressed into a flattenedcoil that occupies only a narrow width of the solar module frontsurface.

FIG. 8G shows a flexible interconnect 400 comprising a thin ribbonsection that is conductively bonded to a terminal front surface contactof a super cell and a thick cross-section portion located adjacent tothe super cell.

In FIGS. 8A-8G, flexible interconnects 400 may extend along the fulllengths of the edges of the super cells (e.g., into the drawing page) asshown in FIG. 6 for example.

Optionally, portions of a flexible interconnect 400 that are otherwisevisible from the front of the module may be covered by a dark film orcoating or otherwise colored to reduce visible contrast between theinterconnect and the super cell, as perceived by a human having normalcolor vision. For example, in FIG. 8C optional black film or coating 425covers portions of the interconnect 400 that would otherwise be visiblefrom the front of the module. Otherwise visible portions of interconnect400 shown in the other figures may be similarly covered or colored.

Conventional solar modules typically include three or more bypassdiodes, with each bypass diode connected in parallel with a seriesconnected group of 18-24 silicon solar cells. This is done to limit theamount of power that may be dissipated as heat in a reverse biased solarcell. A solar cell may become reverse biased, for example, because of adefect, a dirty front surface, or uneven illumination that reduces itsability to pass current generated in the string. Heat generated in asolar cell in reverse bias depends on the voltage across the solar celland the current through the solar cell. If the voltage across thereverse biased solar cell exceeds the breakdown voltage of the solarcell, the heat dissipated in the cell will be equal to the breakdownvoltage times the full current generated in the string. Silicon solarcells typically have a breakdown voltage of 16-30 Volts. Because eachsilicon solar cell produces a voltage of about 0.64 Volts in operation,a string of more than 24 solar cells could produce a voltage across areverse biased solar cell exceeding the breakdown voltage.

In conventional solar modules in which the solar cells are spaced apartfrom each other and interconnected with ribbons, heat is not readilytransported away from a hot solar cell. Consequently, the powerdissipated in a solar cell at breakdown voltage could produce a hot spotin the solar cell that causes significant thermal damage and perhaps afire. In conventional solar modules a bypass diode is therefore requiredfor every group of 18-24 series connected solar cells to insure that nosolar cell in the string can be reverse biased above the breakdownvoltage.

Applicants have discovered that heat is readily transported along asilicon super cell through the thin electrically and thermallyconductive bonds between adjacent overlapping silicon solar cells.Further, the current through a super cell in the solar modules describedherein is typically less than that through a string of conventionalsolar cells, because the super cells described herein are typicallyformed by shingling rectangular solar cells each of which has an activearea less than (for example, ⅙) that of a conventional solar cell.Furthermore, the rectangular aspect ratio of the solar cells typicallyemployed herein provides extended regions of thermal contact betweenadjacent solar cells. As a consequence, less heat is dissipated in asolar cell reverse biased at the breakdown voltage, and the heat readilyspreads through the super cell and the solar module without creating adangerous hot spot. Applicants have therefore recognized that solarmodules formed from super cells as described herein may employ far fewerbypass diodes than conventionally believed to be required.

For example, in some variations of solar modules as described herein asuper cell comprising N≧25 solar cells, N≧about 30 solar cells, N≧about50 solar cells, N≧about 70 solar cells, or N≧about 100 solar cells maybe employed with no single solar cell or group of <N solar cells in thesuper cell individually electrically connected in parallel with a bypassdiode. Optionally, a full super cell of these lengths may beelectrically connected in parallel with a single bypass diode.Optionally, super cells of these lengths may be employed without abypass diode.

Several additional and optional design features may make solar modulesemploying super cells as described herein even more tolerant to heatdissipated in a reverse biased solar cell. Referring again to FIGS.8A-8C, encapsulant 410 may be or comprise a thermoplastic olefin (TPO)polymer, TPO encapsulants are more photo-thermal stable than standardethylene-vinyl acetate (EVA) encapsulants. EVA will brown withtemperature and ultraviolet light and lead to hot spot issues created bycurrent limiting cells. These problems are reduced or avoided with TPOencapsulant. Further, the solar modules may have a glass-glass structurein which both the transparent front sheet 420 and the back sheet 430 areglass. Such a glass-glass enables the solar module to safely operate attemperatures greater than those tolerated by a conventional polymer backsheet. Further still, junction boxes may be mounted on one or more edgesof a solar module, rather than behind the solar module where a junctionbox would add an additional layer of thermal insulation to the solarcells in the module above it.

FIG. 9A shows an example rectangular solar module comprising sixrectangular shingled super cells arranged in six rows extending thelength of the long sides of the solar module. The six super cells areelectrically connected in parallel with each other and with a bypassdiode disposed in a junction box 490 on the rear surface of the solarmodule. Electrical connections between the super cells and the bypassdiode are made through ribbons 450 embedded in the laminate structure ofthe module.

FIG. 9B shows another example rectangular solar module comprising sixrectangular shingled super cells arranged in six rows extending thelength of the long sides of the solar module. The super cells areelectrically connected in parallel with each other. Separate positive490P and negative 490N terminal junction boxes are disposed on the rearsurface of the solar module at opposite ends of the solar module. Thesuper cells are electrically connected in parallel with a bypass diodelocated in one of the junction boxes by an external cable 455 runningbetween the junction boxes.

FIGS. 9C-9D show an example glass-glass rectangular solar modulecomprising six rectangular shingled super cells arranged in six rowsextending the length of the long sides of the solar module in alamination structure comprising glass front and back sheets. The supercells are electrically connected in parallel with each other. Separatepositive 490P and negative 490N terminal junction boxes are mounted onopposite edges of the solar module.

Shingled super cells open up unique opportunities for module layout withrespect to module level power management devices (for example, DC/ACmicro-inverters, DC/DC module power optimizers, voltage intelligence andsmart switches, and related devices). The key feature of module levelpower management systems is power optimization. Super cells as describedand employed herein may produce higher voltages than traditional panels.In addition, super cell module layout may further partition the module.Both higher voltages and increased partitioning create potentialadvantages for power optimization.

FIG. 9E shows one example architecture for module level power managementusing shingled super cells. In this figure an example rectangular solarmodule comprises six rectangular shingled super cells arranged in sixrows extending the length of the long sides of the solar module. Threepairs of super cells are individually connected to a power managementsystem 460, enabling more discrete power optimization of the module.

FIG. 9F shows another example architecture for module level powermanagement using shingled super cells. In this figure an examplerectangular solar module comprises six rectangular shingled super cellsarranged in six rows extending the length of the long sides of the solarmodule. The six super cells are individually connected to a powermanagement system 460, enabling yet more discrete power optimization ofthe module.

FIG. 9G shows another example architecture for module level powermanagement using shingled super cells. In this figure an examplerectangular solar module comprises six or more rectangular shingledsuper cells 998 arranged in six or more rows, where the three or moresuper cells pairs are individually connected to a bypass diode or apower management system 460, to allow yet more discrete poweroptimization of the module.

FIG. 9H shows another example architecture for module level powermanagement using shingled super cells. In this figure an examplerectangular solar module comprises six or more rectangular shingledsuper cells 998 arranged in six or more rows, where each two super cellare connected in series, and all pairs are connected in parallel. Abypass diode or power management system 460 is connected in parallel toall pairs, permitting power optimization of the module.

In some variations, module level power management allows elimination ofall bypass diodes on the solar module while still excluding the risk ofhot spots. This is accomplished by integrating voltage intelligence atthe module level. By monitoring the voltage output of a solar cellcircuit (e.g., one or more super cells) in the solar module, a “smartswitch” power management device can determine if that circuit includesany solar cells in reverse bias. If a reverse biased solar cell isdetected, the power management device can disconnect the correspondingcircuit from the electrical system using, for example, a relay switch orother component. For example, if the voltage of a monitored solar cellcircuit drops below a predetermined threshold (V_(Limit)), then thepower management device will shut off (open circuit) that circuit whileensuring that the module or string of modules remain connected.

In certain embodiments, where a voltage of the circuits drops by morethan a certain percentage or magnitude (e.g., 20% or 10V) from the othercircuits in same solar array, it will be shut off. The electronics willdetect this change based upon inter-module communication.

Implementation of such voltage intelligence may be incorporated intoexisting module level power management solutions (e.g., from EnphaseEnergy Inc., Solaredge Technologies, Inc., Tigo Energy, Inc.) or througha custom circuit design.

One example of how the V_(Limit) threshold voltage may be calculated is:

CellVoc _(@Low Irr & High Temp) ×N _(number of cells in series) −Vrb_(Reverse breakdown voltage) ≦V _(Limit),

where:

-   -   CellVoc_(@Low Irr & High Temp)=open circuit voltage of a cell        working at low irradiation and at high temperature (lowest        expected working Voc);    -   N_(number of cells in series)=a number of cells connected in        series in each super cell monitored.    -   Vrb_(Reverse breakdown voltage)=revered polarity voltage needed        to pass current through a cell.

This approach to module level power management using a smart switch mayallow, for example more than 100 silicon solar cells to be connected inseries within a single module without affecting safety or modulereliability. In addition, such a smart switch can be used to limitstring voltage going to a central inverter. Longer module strings cantherefore be installed without safety or permitting concerns regardingover voltage. The weakest module can be bypassed (switched off) ifstring voltages run up against the limit.

FIGS. 10A, 11A, 12A, 13A, 13B, and 14B described below provideadditional example schematic electrical circuits for solar modulesemploying shingled super cells. FIGS. 10B-1, 10B-2, 11B-1, 11B-2, 11C-1,11C-2, 12B-1, 12B-2, 12C-1, 12C-2, 12C-3, 13C-1, 13C-2, 14C-1, and 14C-2provide example physical layouts corresponding to those schematiccircuits. The description of the physical layouts assumes that the frontsurface end contact of each super cell is of negative polarity and therear surface end contact of each super cell is of positive polarity. Ifinstead the modules employ super cells having front surface end contactsof positive polarity and rear surface end contacts of negative polarity,then the discussion of the physical layouts below may be modified byswapping positive for negative and by reversing the orientation of thebypass diodes. Some of the various buses referred to in the descriptionof these figures may be formed, for example, with interconnects 400described above. Other buses described in these figures may beimplemented, for example, with ribbons embedded in the laminatestructure of solar module or with external cables.

FIG. 10A shows an example schematic electrical circuit for a solarmodule as illustrated in FIG. 5B, in which the solar module includes tenrectangular super cells 100 each of which has a length approximatelyequal to the length of the short sides of the solar module. The supercells are arranged in the solar module with their long sides orientedparallel to the short sides of the module. All of the super cells areelectrically connected in parallel with a bypass diode 480.

FIGS. 10B-1 and 10B-2 show an example physical layout for the solarmodule of FIG. 10A. Bus 485N connects the negative (front surface) endcontacts of super cells 100 to the positive terminal of bypass diode 480in junction box 490 located on the rear surface of the module. Bus 485Pconnects the positive (rear surface) end contacts of super cells 100 tothe negative terminal of bypass diode 480. Bus 485P may lie entirelybehind the super cells. Bus 485N and/or its interconnection to the supercells occupy a portion of the front surface of the module.

FIG. 11A shows an example schematic electrical circuit for a solarmodule as illustrated in FIG. 5A, in which the solar module includestwenty rectangular super cells 100, each of which has a lengthapproximately equal to one half the length of the short sides of thesolar module, and the super cells are arranged end-to-end in pairs toform ten rows of super cells. The first super cell in each row isconnected in parallel with the first super cells in the other rows andin parallel with a bypass diode 500. The second super cell in each rowis connected in parallel with the second super cells in the other rowsand in parallel with a bypass diode 510. The two groups of super cellsare connected in series, as are the two bypass diodes.

FIGS. 11B-1 and 11B-2 show an example physical layout for the solarmodule of FIG. 11A. In this layout the first super cell in each row hasits front surface (negative) end contact along a first side of themodule and its rear surface (positive) end contact along the center lineof the module, and the second super cell in each row has its frontsurface (negative) end contact along the center line of the module andits rear surface (positive) end contact along a second side of themodule opposite from the first side. Bus 515N connects the front surface(negative) end contact of the first super cell in each row to thepositive terminal of bypass diode 500. Bus 515P connects the rearsurface (positive) end contact of the second super cell in each row tothe negative terminal of bypass diode 510. Bus 520 connects the rearsurface (positive) end contact of the first super cell in each row andthe front surface (negative) end contact of the second super cell ineach row to the negative terminal of bypass diode 500 and to thepositive terminal of bypass diode 510.

Bus 515P may lie entirely behind the super cells. Bus 515N and/or itsinterconnection to the super cells occupy a portion of the front surfaceof the module. Bus 520 may occupy a portion of the front surface of themodule, requiring a gap 210 as shown in FIG. 5A. Alternatively, bus 520may lie entirely behind the super cells and be electrically connected tothe super cells with hidden interconnects sandwiched between overlappingends of the super cells. In such a case little or no gap 210 isrequired.

FIGS. 11C-1, 11C-2, and 11C-3 show another example physical layout forthe solar module of FIG. 11A. In this layout the first super cell ineach row has its front surface (negative) end contact along a first sideof the module and its rear surface (positive) end contact along thecenter line of the module, and the second super cell in each row has itsrear surface (positive) end contact along the center line of the moduleand its front surface (negative) end contact along a second side of themodule opposite from the first side. Bus 525N connects the front surface(negative) end contact of the first super cell in each row to thepositive terminal of bypass diode 500. Bus 530N connects the frontsurface (negative) end contact of the second cell in each row to thenegative terminal of bypass diode 500 and to the positive terminal ofbypass diode 510. Bus 535P connects the rear surface (positive) endcontact of the first cell in each row to the negative terminal of bypassdiode 500 and to the positive terminal of bypass diode 510. Bus 540Pconnects the rear surface (positive) end contact of the second cell ineach row to the negative terminal of bypass diode 510.

Bus 535P and bus 540P may lie entirely behind the super cells. Bus 525Nand bus 530N and/or their interconnection to the super cells occupy aportion of the front surface of the module.

FIG. 12A shows another example schematic circuit diagram for a solarmodule as illustrated in FIG. 5A, in which the solar module includestwenty rectangular super cells 100, each of which has a lengthapproximately equal to one half the length of the short sides of thesolar module, and the super cells are arranged end-to-end in pairs toform ten rows of super cells. In the circuit shown in FIG. 12A, thesuper cells are arranged in four groups: in a first group the firstsuper cells of the top five rows are connected in parallel with eachother and with a bypass diode 545, in a second group the second supercells of the top five rows are connected in parallel with each other andwith a bypass diode 505, in a third group the first super cells of thebottom five rows are connected in parallel with each other and with abypass diode 560, and in a fourth group the second super cells of thebottom five rows are connected in parallel with each other and with abypass diode 555. The four groups of super cells are connected in serieswith each other. The four bypass diodes are also in series.

FIGS. 12B-1 and 12B-2 show an example physical layout for the solarmodule of FIG. 12A. In this layout the first group of super cells hasits front surface (negative) end contacts along a first side of themodule and its rear surface (positive) end contacts along the centerline of the module, the second group of super cells has its frontsurface (negative) end contacts along the center line of the module andits rear surface (positive) end contacts along a second side of themodule opposite from the first side, the third group of super cells hasits rear surface (positive) end contacts along the first side of themodule and its front surface (negative) end contacts along the centerline of the module, and the fourth group of super cells has its rearsurface (positive) end contact along the center line of the module andits front surface (negative) end contact along the second side of themodule.

Bus 565N connects the front surface (negative) end contacts of the supercells in the first group of super cells to each other and to thepositive terminal of bypass diode 545. Bus 570 connects the rear surface(positive) end contacts of the super cells in the first group of supercells and the front surface (negative) end contacts of the super cellsin the second group of super cells to each other, to the negativeterminal of bypass diode 545, and to the positive terminal of bypassdiode 550. Bus 575 connects the rear surface (positive) end contacts ofthe super cells in the second group of super cells and the front surface(negative) end contacts of the super cells in the fourth group of supercells to each other, to the negative terminal of bypass diode 550, andto the positive terminal of bypass diode 555. Bus 580 connects the rearsurface (positive) end contacts of the super cells in the fourth groupof super cells and the front surface (negative) end contacts of thesuper cells in the third group of super cells to each other, to thenegative terminal of bypass diode 555, and to the positive terminal ofbypass diode 560. Bus 585P connects the rear surface (positive) endcontacts of the super cells in the third group of super cells to eachother and to the negative terminal of bypass diode 560.

Bus 585P and the portion of bus 575 connecting to the super cells of thesecond group of super cells may lie entirely behind the super cells. Theremaining portion of bus 575 and bus 565N and/or their interconnectionto the super cells occupy a portion of the front surface of the module.

Bus 570 and bus 580 may occupy a portion of the front surface of themodule, requiring a gap 210 as shown in FIG. 5A. Alternatively, they maylie entirely behind the super cells and be electrically connected to thesuper cells with hidden interconnects sandwiched between overlappingends of super cells. In such a case little or no gap 210 is required.

FIGS. 12C-1, 12C-2, and 12C-3 show an alternative physical layout forthe solar module of FIG. 12A. This layout uses two junction boxes 490Aand 490B in place of the single junction box 490 shown in FIGS. 12B-1and 12B-2, but is otherwise equivalent to that of FIGS. 12B-1 and 12B-2.

FIG. 13A shows another example schematic circuit diagram for a solarmodule as illustrated in FIG. 5A, in which the solar module includestwenty rectangular super cells 100, each of which has a lengthapproximately equal to one half the length of the short sides of thesolar module, and the super cells are arranged end-to-end in pairs toform ten rows of super cells. In the circuit shown in FIG. 13A, thesuper cells are arranged in four groups: in a first group the firstsuper cells of the top five rows are connected in parallel with eachother, in a second group the second super cells of the top five rows areconnected in parallel with each other, in a third group the first supercells of the bottom five rows are connected in parallel with each other,and in a fourth group the second super cells of the bottom five rows areconnected in parallel with each other. The first group and the secondgroup are connected in series with each other and thus connected are inparallel with a bypass diode 590. The third group and the fourth groupare connected in series with each other and thus connected in parallelwith another bypass diode 595. The first and second groups are connectedin series with the third and fourth groups, and the two bypass diodesare in series as well.

FIGS. 13C-1 and 13C-2 show an example physical layout for the solarmodule of FIG. 13A. In this layout the first group of super cells hasits front surface (negative) end contact along a first side of themodule and its rear surface (positive) end contact along the center lineof the module, the second group of super cells has its front surface(negative) end contact along the center line of the module and its rearsurface (positive) end contact along a second side of the moduleopposite from the first side, the third group of super cells has itsrear surface (positive) end contact along the first side of the moduleand its front surface (negative) end contact along the center line ofthe module, and the fourth group of super cells has its rear surface(positive) end contact along the center line of the module and its frontsurface (negative) end contact along the second side of the module.

Bus 600 connects the front surface (negative) end contacts of the firstgroup of super cells to each other, to the rear surface (positive) endcontacts of the third group of super cells, to the positive terminal ofbypass diode 590, and to the negative terminal of bypass diode 595. Bus605 connects the rear surface (positive) end contacts of the first groupof super cells to each other and to the front surface (negative) endcontacts of the second group of super cells. Bus 610P connects the rearsurface (positive) end contacts of the second group of super cells toeach other and to the negative terminal of bypass diode 590. Bus 615Nconnects the front surface (negative) end contacts of the fourth groupof super cells to each other and to the positive terminal of bypassdiode 595. Bus 620 connects the front surface (negative) end contacts ofthe third group of super cells to each other and to the rear surface(positive) end contacts of the fourth group of super cells.

Bus 610P and the portion of bus 600 connecting to the super cells of thethird group of super cells may lie entirely behind the super cells. Theremaining portion of bus 600 and bus 615N and/or their interconnectionto the super cells occupy a portion of the front surface of the module.

Bus 605 and bus 620 occupy a portion of the front surface of the module,requiring a gap 210 as shown in FIG. 5A. Alternatively, they may lieentirely behind the super cells and be electrically connected to thesuper cells with hidden interconnects sandwiched between overlappingends of super cells. In such a case little or no gap 210 is required.

FIG. 13B shows an example schematic electrical circuit for a solarmodule as illustrated in FIG. 5B, in which the solar module includes tenrectangular super cells 100 each of which has a length approximatelyequal to the length of the short sides of the solar module. The supercells are arranged in the solar module with their long sides orientedparallel to the short sides of the module. In the circuit shown in FIG.13B, the super cells are arranged in two groups: in a first group thetop five super cells are connected in parallel with each other and withbypass diode 590, and in a second group the bottom five super cells areconnected in parallel with each other and with bypass diode 595. The twogroups are connected in series with each other. The bypass diodes arealso connected in series.

The schematic circuit of FIG. 13B differs from that of FIG. 13A byreplacing each row of two super cells in FIG. 13A with a single supercell. Consequently, the physical layout for the solar module of FIG. 13Bmay be as shown in FIGS. 13C-1, 13C-2, and 13C-3, with the omission ofbus 605 and bus 620.

FIG. 14A shows an example rectangular solar module 700 comprisingtwenty-four rectangular super cells 100, each of which has a lengthapproximately equal to one half the length of the short sides of thesolar module. Super cells are arranged end-to-end in pairs to formtwelve rows of super cells, with the rows and the long sides of thesuper cells oriented parallel to the short sides of the solar module.

FIG. 14B shows an example schematic circuit diagram for a solar moduleas illustrated in FIG. 14A. In the circuit shown in FIG. 14B, the supercells are arranged in three groups: in a first group the first supercells of the top eight rows are connected in parallel with each otherand with a bypass diode 705, in a second group the super cells of thebottom four rows are connected in parallel with each other and with abypass diode 710, and in a third group the second super cells of the topeight rows are connected in parallel with each other and with a bypassdiode 715. The three groups of super cells are connected in series. Thethree bypass diodes are also in series.

FIGS. 14C-1 and 14C-2 show an example physical layout for the solarmodule of FIG. 14B. In this layout the first group of super cells hasits front surface (negative) end contacts along a first side of themodule and its rear surface (positive) end contacts along the centerline of the module. In the second group of super cells, the first supercell in each of the bottom four rows has its rear surface (positive) endcontact along the first side of the module and its front surface(negative) end contact along the center line of the module, and thesecond super cell in each of the bottom four rows has its front surface(negative) end contact along the center line of the module and its rearsurface (positive) end contact along a second side of the moduleopposite from the first side. The third group of solar cells has itsrear surface (positive) end contacts along the center line of the moduleand its rear surface (negative) end contacts along the second side ofthe module.

Bus 720N connects the front surface (negative) end contacts of the firstgroup of super cells to each other and to the positive terminal ofbypass diode 705. Bus 725 connects the rear surface (positive) endcontacts of the first group of super cells to the front surface(negative) end contacts of the second group of super cells, to thenegative terminal of bypass diode 705, and to the positive terminal ofbypass diode 710. Bus 730P connects the rear surface (positive) endcontacts of the third group of super cells to each other and to thenegative terminal of bypass diode 715. Bus 735 connects the frontsurface (negative) end contacts of the third group of super cells toeach other, to the rear surface (positive) end contacts of the secondgroup of super cells, to the negative terminal of bypass diode 710, andto the positive terminal of bypass diode 715.

The portion of bus 725 connecting to the super cells of the first groupof super cells, bus 730P, and the portion of bus 735 connecting to thesuper cells of the second group of super cells may lie entirely behindthe super cells. Bus 720N and the remaining portions of bus 725 and bus735 and/or their interconnection to the super cells occupy a portion ofthe front surface of the module.

Some of the examples described above house the bypass diodes in one ormore junction boxes on the rear surface of the solar module. This is notrequired, however. For example, some or all of the bypass diodes may bepositioned in-plane with the super cells around the perimeter of thesolar module or in gaps between super cells, or positioned behind thesuper cells. In such cases the bypass diodes may be disposed in alaminate structure in which the super cells are encapsulated, forexample. The locations of the bypass diodes may thus be decentralizedand removed from the junction boxes, facilitating replacement of acentral junction box comprising both positive and negative moduleterminals with two separate single-terminal junction boxes which may belocated on the rear surface of the solar module near to outer edges ofthe solar module, for example. This approach generally reduces thecurrent path length in ribbon conductors in the solar module and incabling between solar modules, which may both reduce material cost andincrease module power (by reducing resistive power losses).

Referring to FIG. 15, for example, the physical layout for variouselectrical interconnections for a solar module as illustrated in FIG. 5Bhaving the schematic circuit diagram of FIG. 10A may employ a bypassdiode 480 located in the super cell laminate structure and two singleterminal junction boxes 490P and 490N. FIG. 15 may best be appreciatedby comparison to FIGS. 10B-1 and 10B-2. The other module layoutsdescribed above may be similarly modified.

Use of in-laminate bypass diodes as just described may be facilitated bythe use of reduced current (reduced area) rectangular solar cells asdescribed above, because the power dissipated in a forward-biased bypassdiode by the reduced current solar cells may be less than would be thecase for conventionally sized solar cells. Bypass diodes in solarmodules described in this specification may therefore require lessheat-sinking than is conventional, and consequently may be moved out ofa junction box on the rear surface of the module and into the laminate.

A single solar module may include interconnects, other conductors,and/or bypass diodes supporting two or more electrical configurations,for example supporting two or more of the electrical configurationsdescribed above. In such cases a particular configuration for operationof the solar module may be selected from the two or more alternativeswith the use of switches and/or jumpers, for example. The differentconfigurations may put different numbers of super cells in series and/orin parallel to provide different combinations of voltage and currentoutputs from the solar module. Such a solar module may therefore befactory or field configurable to select from two or more differentvoltage and current combinations, for example to select between a highvoltage and low current configuration, and a low voltage and highcurrent configuration.

FIG. 16 shows an example arrangement of a smart switch module levelpower management device 750, as described above, between two solarmodules.

Referring now to FIG. 17, an example method 800 for making solar modulesas disclosed in this specification comprises the following steps. Instep 810, conventionally sized solar cells (e.g., 156 millimeters×156millimeters or 125 millimeters×125 millimeters) are cut and/or cleavedto form narrow rectangular solar cell “strips”. (See also FIGS. 3A-3E)and related description above, for example). The resulting solar cellstrips may optionally be tested and sorted according to theircurrent-voltage performance. Cells with matching or approximatelymatching current-voltage performance may advantageously be used in thesame super cell or in the same row of series connected super cells. Forexample, it may be advantageous that cells connected in series within asuper cell or within a row of super cells produce matching orapproximately matching current under the same illumination.

In step 815 super cells are assembled from the strip solar cells, with aconductive adhesive bonding material disposed between overlappingportions of adjacent solar cells in the super cells. The conductiveadhesive bonding material may be applied, for example, by ink jetprinting or screen printing.

In step 820 heat and pressure are applied to cure or partially cure theconductive adhesive bonding material between the solar cells in thesuper cells. In one variation, as each additional solar cell is added toa super cell the conductive adhesive bonding material between the newlyadded solar cell and its adjacent overlapping solar cell (already partof the super cell) is cured or partially cured, before the next solarcell is added to the super cell. In another variation, more than twosolar cells or all solar cells in a super cell may be positioned in thedesired overlapping manner before the conductive adhesive bondingmaterial is cured or partially cured. The super cells resulting fromthis step may optionally be tested and sorted according to theircurrent-voltage performance. Super cells with matching or approximatelymatching current-voltage performance may advantageously be used in thesame row of super cells or in the same solar module. For example, it maybe advantageous that super cells or rows of super cells electricallyconnected in parallel produce matching or approximately matchingvoltages under the same illumination.

In step 825 the cured or partially cured super cells are arranged andinterconnected in the desired module configuration in a layeredstructured including encapsulant material, a transparent front (sunside) sheet, and a (optionally transparent) back sheet. The layeredstructure may comprise, for example, a first layer of encapsulant on aglass substrate, the interconnected super cells arranged sun-side downon the first layer of encapsulant, a second layer of encapsulant on thelayer of super cells, and a back sheet on the second layer ofencapsulant. Any other suitable arrangement may also be used.

In lamination step 830 heat and pressure are applied to the layeredstructure to form a cured laminate structure.

In one variation of the method of FIG. 17, the conventionally sizedsolar cells are separated into solar cell strips, after which theconductive adhesive bonding material is applied to each individual solarcell strip. In an alternative variation, the conductive adhesive bondingmaterial is applied to the conventionally sized solar cells prior toseparation of the solar cells into solar cell strips.

At curing step 820 the conductive adhesive bonding material may be fullycured, or it may be only partially cured. In the latter case theconductive adhesive bonding material may be initially partially cured atstep 820 sufficiently to ease handling and interconnection of the supercells, and fully cured during the subsequent lamination step 830.

In some variations a super cell 100 assembled as an intermediate productin method 800 comprises a plurality of rectangular solar cells 10arranged with the long sides of adjacent solar cells overlapped andconductively bonded as described above, and interconnects bonded toterminal contacts at opposite ends of the super cell.

FIG. 30A shows an example super cell with electrical interconnectsbonded to its front and rear surface terminal contacts. The electricalinterconnects run parallel to the terminal edges of the super cell andextend laterally beyond the super cell to facilitate electricalinterconnection with an adjacent super cell.

FIG. 30B shows two of the super cells of FIG. 30A interconnected inparallel.

Portions of the interconnects that are otherwise visible from the frontof the module may be covered or colored (e.g., darkened) to reducevisible contrast between the interconnect and the super cells, asperceived by a human having normal color vision. In the exampleillustrated in FIG. 30A, an interconnect 850 is conductively bonded to afront side terminal contact of a first polarity (e.g., + or −) at oneend of the super cell (on the right side of the drawing), and anotherinterconnect 850 is conductively bonded to a back side terminal contactof the opposite polarity at the other end of the super cell (on the leftside of the drawing). Similarly to the other interconnects describedabove, interconnects 850 may be conductively bonded to the super cellwith the same conductive adhesive bonding material used between solarcells, for example, but this is not required. In the illustratedexample, a portion of each interconnect 850 extends beyond the edge ofsuper cell 100 in a direction perpendicular to the long axis of thesuper cell (and parallel to the long axes of solar cells 10). As shownin FIG. 30B, this allows two or more super cells 100 to be positionedside by side, with the interconnects 850 of one super cell overlappingand conductively bonded to corresponding interconnects 850 on theadjacent super cell to electrically interconnect the two super cells inparallel. Several such interconnects 850 interconnected in series asjust described may form a bus for the module. This arrangement may besuitable, for example, when the individual super cell extends the fullwidth or full length of the module (e.g., FIG. 5B). In addition,interconnects 850 may also be used to electrically connect terminalcontacts of two adjacent super cells within a row of super cells inseries. Pairs or longer strings of such interconnected super cellswithin a row may be electrically connected in parallel with similarlyinterconnected super cells in an adjacent row by overlapping andconductively bonding interconnects 850 in one row with interconnects 850in the adjacent row similarly to as shown in FIG. 30B.

Interconnect 850 may be die cut from a conducting sheet, for example,and may be optionally patterned to increase its mechanical complianceboth perpendicular to and parallel to the edge of the super cell toreduce or accommodate stress perpendicular and parallel to the edge ofthe super cell arising from mismatch between the CTE of the interconnectand that of the super cell. Such patterning may include, for example,slits, slots, or holes (not shown). The mechanical compliance ofinterconnect 850, and its bond or bonds to the super cell, should besufficient for the connections to the super cell to survive stressarising from CTE mismatch during the lamination process described inmore detail below. Interconnect 850 may be bonded to the super cellwith, for example, a mechanically compliant electrically conductivebonding material as described above for use in bonding overlapped solarcells. Optionally, the electrically conductive bonding material may belocated only at discrete positions along the edges of the super cellrather than in a continuous line extending substantially the length ofthe edge of the super cell, to reduce or accommodate stress parallel tothe edges of the super cell arising from mismatch between thecoefficient of thermal expansion of the electrically conductive bondingmaterial or the interconnects and that of the super cell.

Interconnect 850 may be cut from a thin copper sheet, for example, andmay be thinner than conventional conductive interconnects when supercells 100 are formed from solar cells having areas smaller than standardsilicon solar cells and therefore operate at lower currents than isconventional. For example, interconnects 850 may be formed from coppersheet having a thickness of about 50 microns to about 300 microns.Interconnects 850 may be sufficiently thin and flexible to fold aroundand behind the edge of the super cell to which they are bonded,similarly to the interconnects described above.

FIGS. 19A-19D show several example arrangements by which heat andpressure may be applied during method 800 to cure or partially cure theconductive adhesive bonding material between adjacent solar cells in thesuper cells. Any other suitable arrangement may also be employed.

In FIG. 19A, heat and localized pressure are applied to cure orpartially cure conductive adhesive bonding material 12 one joint(overlapping region) at a time. The super cell may be supported by asurface 1000 and pressure may be mechanically applied to the joint fromabove with a bar, pin, or other mechanical contact, for example. Heatmay be applied to the joint with hot air (or other hot gas), with aninfrared lamp, or by heating the mechanical contact that applieslocalized pressure to the joint, for example.

In FIG. 19B, the arrangement of FIG. 19A is extended to a batch processthat simultaneously applies heat and localized pressure to multiplejoints in a super cell.

In FIG. 19C, an uncured super cell is sandwiched between release liners1015 and reusable thermoplastic sheets 1020 and positioned on a carrierplate 1010 supported by a surface 1000. The thermoplastic material ofsheets 1020 is selected to melt at the temperature at which the supercells are cured. Release liners 1015 may be formed from fiberglass andPTFE, for example, and do not adhere to the super cell after the curingprocess. Preferably, release liners 1015 are formed from materials thathave a coefficient of thermal expansion matching or substantiallymatching that of the solar cells (e.g., the CTE of silicon). This isbecause if the CTE of the release liners differs too much from that ofthe solar cells, then the solar cells and the release liners willlengthen by different amounts during the curing process, which wouldtend to pull the super cell apart lengthwise at the joints. A vacuumbladder 1005 overlies this arrangement. The uncured super cell is heatedfrom below through surface 1000 and carrier plate 1010, for example, anda vacuum is pulled between bladder 1005 and support surface 1000. As aresult bladder 1005 applies hydrostatic pressure to the super cellthrough the melted thermoplastic sheets 1020.

In FIG. 19D, an uncured super cell is carried by a perforated movingbelt 1025 through an oven 1035 that heats the super cell. A vacuumapplied through perforations in the belt pulls solar cells 10 toward thebelt, thereby applying pressure to the joints between them. Theconductive adhesive bonding material in those joints cures as the supercell passes through the oven. Preferably, perforated belt 1025 is formedfrom materials that have a CTE matching or substantially matching thatof the solar cells (e.g., the CTE of silicon). This is because if theCTE of belt 1025 differs too much from that of the solar cells, then thesolar cells and the belt will lengthen by different amounts in oven1035, which will tend to pull the super cell apart lengthwise at thejoints.

Method 800 of FIG. 17 includes distinct super cell curing and laminationsteps, and produces an intermediate super cell product. In contrast, inmethod 900 shown in FIG. 18 the super cell curing and lamination stepsare combined. In step 910, conventionally sized solar cells (e.g., 156millimeters×156 millimeters or 125 millimeters×125 millimeters) are cutand/or cleaved to form narrow rectangular solar cell strips. Theresulting solar cell strips may optionally be tested and sorted.

In step 915, the solar cell strips are arranged in the desired moduleconfiguration in a layered structured including encapsulant material, atransparent front (sun side) sheet, and a back sheet. The solar cellstrips are arranged as super cells, with an uncured conductive adhesivebonding material disposed between overlapping portions of adjacent solarcells in the super cells. (The conductive adhesive bonding material maybe applied, for example, by ink jet printing or screen printing).Interconnects are arranged to electrically interconnect the uncuredsuper cells in the desired configuration. The layered structure maycomprise, for example, a first layer of encapsulant on a glasssubstrate, the interconnected super cells arranged sun-side down on thefirst layer of encapsulant, a second layer of encapsulant on the layerof super cells, and a back sheet on the second layer of encapsulant. Anyother suitable arrangement may also be used.

In lamination step 920 heat and pressure are applied to the layeredstructure to cure the conductive adhesive bonding material in the supercells and to form a cured laminate structure. Conductive adhesivebonding material used to bond interconnects to the super cells may becured in this step as well.

In one variation of method 900, the conventionally sized solar cells areseparated into solar cell strips, after which the conductive adhesivebonding material is applied to each individual solar cell strips. In analternative variation, the conductive adhesive bonding material isapplied to the conventionally sized solar cells prior to separation ofthe solar cells into solar cell strips. For example, a plurality ofconventionally sized solar cells may be placed on a large template,conductive adhesive bonding material then dispensed on the solar cells,and the solar cells then simultaneously separated into solar cell stripswith a large fixture. The resulting solar cell strips may then betransported as a group and arranged in the desired module configurationas described above.

As noted above, in some variations of method 800 and of method 900 theconductive adhesive bonding material is applied to the conventionallysized solar cells prior to separating the solar cells into solar cellstrips. The conductive adhesive bonding material is uncured (i.e., still“wet”) when the conventionally sized solar cell is separated to form thesolar cell strips. In some of these variations, the conductive adhesivebonding material is applied to a conventionally sized solar cell (e.g.by ink jet or screen printing), then a laser is used to scribe lines onthe solar cell defining the locations at which the solar cell is to becleaved to form the solar cell strips, then the solar cell is cleavedalong the scribe lines. In these variations the laser power and/or thedistance between the scribe lines and the adhesive bonding material maybe selected to avoid incidentally curing or partially curing theconductive adhesive bonding material with heat from the laser. In othervariations, a laser is used to scribe lines on a conventionally sizedsolar cell defining the locations at which the solar cell is to becleaved to form the solar cell strips, then the conductive adhesivebonding material is applied to the solar cell (e.g. by ink jet or screenprinting), then the solar cell is cleaved along the scribe lines. In thelatter variations it may be preferable to accomplish the step ofapplying the conductive adhesive bonding material without incidentallycleaving or breaking the scribed solar cell during this step.

FIG. 20A schematically illustrates a side view of an example apparatus1050 that may be used to cleave scribed solar cells to which conductiveadhesive bonding material has been applied. (Scribing and application ofconductive adhesive bonding material may have occurred in either order).In this apparatus, a scribed conventionally sized solar cell 45 to whichconductive adhesive bonding material has been applied is carried by aperforated moving belt 1060 over a curved portion of a vacuum manifold1070. As solar cell 45 passes over the curved portion of the vacuummanifold, a vacuum applied through the perforations in the belt pullsthe bottom surface of solar cell 45 against the vacuum manifold andthereby flexes the solar cell. The radius of curvature R of the curvedportion of the vacuum manifold may be selected so that flexing solarcell 45 in this manner cleaves the solar cell along the scribe lines.Advantageously, solar cell 45 may be cleaved by this method withoutcontacting the top surface of solar cell 45 to which the conductiveadhesive bonding material has been applied.

If it is preferred for cleaving to begin at one end of a scribe line(i.e., at one edge of solar cell 45), this may be accomplished withapparatus 1050 of FIG. 20A by for example arranging for the scribe linesto be oriented at an angle θ to the vacuum manifold so that for eachscribe line one end reaches the curved portion of the vacuum manifoldbefore the other end. As shown in FIG. 20B, for example, the solar cellsmay be oriented with their scribe lines at an angle to the direction oftravel of the belt and the manifold oriented perpendicularly to thedirection of travel of the belt. As another example, FIG. 20C shows thecells oriented with their scribe lines perpendicular to the direction oftravel of the belt, and the manifold oriented at an angle.

Any other suitable apparatus may also be used to cleave scribed solarcells to which conductive adhesive bonding material has been applied toform strip solar cells with pre-applied conductive adhesive bondingmaterial. Such apparatus may, for example, use rollers to apply pressureto the top surface of the solar cell to which the conductive adhesivebonding material has been applied. In such cases it is preferable thatthe rollers touch the top surface of the solar cell only in regions towhich conductive adhesive bonding material has not been applied.

In some variations, solar modules comprise super cells arranged in rowson a white or otherwise reflective back sheet, so that a portion ofsolar radiation initially unabsorbed by and passing through the solarcells may be reflected by the back sheet back into the solar cells toproduce electricity. The reflective back sheet may be visible throughthe gaps between rows of super cells, which may result in a solar modulethat appears to have rows of parallel bright (e.g., white) lines runningacross its front surface. Referring to FIG. 5B, for example, theparallel dark lines running between the rows of super cells 100 mayappear as white lines if super cells 100 are arranged on a white backsheet. This may be aesthetically displeasing for some uses of the solarmodules, for example on roof tops.

Referring to FIG. 2I, to improve the aesthetic appearance of the solarmodule, some variations employ a white back sheet 1100 comprising darkstripes 1105 located in positions corresponding to the gaps between rowsof the super cells to be arranged on the back sheet. Stripes 1105 aresufficiently wide that the white portions of the back sheet are notvisible through gaps between the rows of super cells in the assembledmodule. This reduces the visual contrast between the super cells and theback sheet, as perceived by a human having normal color vision. Theresulting module includes a white back sheet but may have a frontsurface similar in appearance to that of the modules illustrated inFIGS. 5A-5B, for example. Dark stripes 1105 may be produced with lengthsof dark tape, for example, or in any other suitable manner.

As previously mentioned, shading of individual cells within solarmodules can create ‘hotspots’, wherein power of the non-shaded cells isdissipated in the shaded cell. This dissipated power creates localizedtemperature spikes that can degrade the modules.

To minimize the potential severity of these hotspots, bypass diodes areconventionally inserted as part of the module. The maximal number ofcells between bypass diodes is set to limit the max temperature of themodule and prevent irreversible damage on the module. Standard layoutsfor silicon cells may utilize a bypass diode every 20 or 24 cells, anumber that is determined by the typical break down voltage of siliconcells. In certain embodiments, the breakdown voltage may lie in rangebetween about 10-50V. In certain embodiments, the breakdown voltage maybe about 10V, about 15V, about 20V, about 25V, about 30V, or about 35V.

According to embodiments, the shingling of strips of cut solar cellswith thin thermally conductive adhesives, improves the thermal contactbetween solar cells. This enhanced thermal contact allows higher degreeof thermal spreading than traditional interconnection technologies. Sucha thermal heat spreading design based on shingling allows longer stringsof solar cells to be used than the twenty-four (or fewer) solar cellsper bypass diode to which conventional designs are restricted. Suchrelaxation in the requirement for frequent bypass diodes according tothe thermal spreading facilitated by shingling according to embodiments,may offer one or more benefits. For example, it allows for the creationof module layouts of a variety of solar cell string lengths, unhinderedby a need to provide for a large number of bypass diodes.

According to embodiments, thermal spreading is achieved by maintaining aphysical and thermal bond with the adjacent cell. This allows foradequate heat dissipation though the bonded joint.

In certain embodiments this joint is maintained at a thickness of about200 micrometers or less, and runs the length of the solar cell in asegmented pattern. Depending upon the embodiment, the joint may have athickness of about 200 micrometers or less, of about 150 micrometers orless, of about 125 micrometers or less, of about 100 micrometers orless, of about 90 micrometers or less, of about 80 micrometers or less,of about 70 micrometers or less, of about 50 micrometers, or less, or ofabout 25 micrometers or less.

An accurate adhesive cure processing may be important to ensuring that areliable joint is maintained while a thickness is reduced in order topromote thermal spreading between bonded cells.

Being allowed to run longer strings (e.g., more than 24 cells) affordsflexibility in the design of solar cells and modules. For example,certain embodiments may utilize strings of cut solar cells that areassembled in a shingled manner. Such configurations may utilizesignificantly more cells per module than a conventional module.

Absent the thermal spreading property, a bypass diode would be neededevery 24 cells. Where the solar cells are cut by ⅙, the bypass diodesper module would be 6 times the conventional module (comprises of 3uncut cells), adding up to a total of 18 diodes. Thus thermal spreadingaffords a significant reduction in the number of bypass diodes.

Moreover for every bypass diode, bypass circuitry is needed to completethe bypass electrical path. Each diode requires two interconnectionspoints and conductor routing to connect them to such interconnectionpoints. This creates a complicated circuit, contributing significantexpense over standard layout costs associated with assembling a solarmodule.

By contrast, thermal spreading technology requires only one or even nobypass diodes per module. Such a configuration streamlines a moduleassembly process, allowing simple automation tools to perform the layoutmanufacturing steps.

Avoiding the need to bypass protect every 24 cells thus renders the cellmodule easier to manufacture. Complex tap-outs in the middle of themodule and long parallel connections for bypass circuitry, are avoided.This thermal spreading is implemented by creating long shingled stripsof cells running a width and/or length of the module.

In addition to providing thermal heat spreading, shingling according toembodiments also allows improved hotspot performance by reducing amagnitude of current dissipated in a solar cell. Specifically, during ahot spot condition the amount of current dissipated in a solar cell isdependent upon cell area.

Since shingling may cut cells to smaller areas, an amount of currentpassing through one cell in a hot spot condition is a function of thecut dimensions. During a hot spot condition, the current passes throughthe lowest resistance path which is usually a cell level defectinterface or grain boundary. Reducing this current is a benefit andminimizes reliability risk failure under hot spot conditions.

FIG. 22A shows a plan view of a conventional module 2200 utilizingtraditional ribbon connections 2201, under hot spot conditions. Here,shading 2202 on one cell 2204 results in heat being localized to thatsingle cell.

By contrast, FIG. 22B shows a plan view of a module utilizing thermalspreading, also under hot spot conditions. Here, shading 2250 on cell2252 generates heat within that cell. This heat, however, is spread toother electrically and thermally bonded cells 2254 within the module2256.

It is further noted that the benefit of reduction in dissipated currentis multiplied for multi-crystalline solar cells. Such multi-crystallinecells are known to perform poorly under hot spot conditions owing to ahigh level of defect interfaces.

As indicated above, particular embodiments may employ shingling ofchamfered cut cells. In such cases, there is a heat spreading advantageto mirror, along the bond line between each cell with the adjacent cell.

This maximizes the bond length of each overlapping joint. Since the bondjoint is major interface for cell-to-cell heat spreading, maximizingthis length may ensure the optimum heat spreading is obtained.

FIG. 23A shows one example of a super cell string layout 2300 withchamfered cells 2302. In this configuration, the chamfered cells areoriented in a same direction, and thus all the bonded joints conductionpaths are the same (125 mm).

Shading 2306 on one cell 2304 results in reverse biasing of that cell.Heat is spread to with adjacent cells. Unbonded ends 2304 a of thechamfered cell becomes hottest due to a longer conduction length to thenext cell.

FIG. 23B shows another example of a super cell string layout 2350 withchamfered cells 2352. In this configuration, the chamfered cells areoriented in different directions, with some of the long edges of thechamfered cells facing each other. This results in bonded jointconduction paths of two lengths: 125 mm and 156 mm.

Where a cell 2354 experiences shading 2356, the configuration of FIG.23B exhibits improved thermal spreading along the longer bond length.FIG. 23B thus shows that the thermal spreading in a super cell withchamfered cells facing each other.

The above discussion has focused upon assembling a plurality of solarcells (which may be cut solar cells) in a shingled manner on a commonsubstrate. This results in the formation of a module having a singleelectrical interconnect—junction box (or j-box).

In order to gather a sufficient amount of solar energy to be useful,however, an installation typically comprises a number of such modulesthat are themselves assembled together. According to embodiments, aplurality of solar cell modules may also be assembled in a shingledmanner to increase the area efficiency of an array.

In particular embodiments, a module may feature a top conductive ribbonfacing a direction of solar energy, and a bottom conductive ribbonfacing away from the direction of solar energy.

The bottom ribbon is buried beneath the cells. Thus, it does not blockincoming light and adversely impact an area efficiency of the module. Bycontrast, the top ribbon is exposed and can block the incoming light andadversely impact efficiency.

According to embodiments the modules themselves can be shingled, suchthat the top ribbon is covered by the neighboring module. FIG. 24 showsa simplified cross-sectional view of such an arrangement 2400, where anend portion 2401 of an adjacent module 2402, serves to overlap the topribbon 2404 of an instant module 2406. Each module itself comprises aplurality of shingled solar cells 2407.

The bottom ribbon 2408 of the instant module 2406 is buried. It islocated on an elevated side of the instant shingled module in order tooverlap the next adjacent shingled module.

This shingled module configuration could also provide for additionalarea on the module for other elements, without adversely impacting afinal exposed area of the module array. Examples of module elements thatmay be positioned in overlapping regions can include but are not limitedto, junction boxes (j-boxes) 2410 and/or bus ribbons.

FIG. 25 shows another embodiment of a shingled module configuration2500. Here, j-boxes 2502, 2504 of the respective adjacent shingledmodules 2506 and 2508 are in a mating arrangement 2510 in order toachieve electrical connection between them. This simplifies theconfiguration of the array of shingled modules by eliminating wiring.

In certain embodiments, the j-boxes could be reinforced and/or combinedwith additional structural standoffs. Such a configuration could createan integrated tilted module roof mount rack solution, wherein adimension of the junction box determines a tilt. Such an implementationmay be particularly useful where an array of shingled modules is mountedon a flat roof.

Where the modules comprise a glass substrate and a glass cover(glass-glass modules), the modules could be used without additionalframe members by shortening an overall module length (and hence anexposed length L resulting from the shingling). Such shortening wouldallow the modules of the tiled array to survive expected physical loads(e.g., a 5400 Pa snow load limit), without fracturing under the strain.

It is emphasized that the use of super cell structures comprising aplurality of individual solar cells assembled in a shingled manner,readily accommodates changing the length of the module to meet aspecific length dictated by physical load and other requirements.

1. A solar module comprising:

a series connected string of N≧25 rectangular or substantiallyrectangular solar cells having on average a breakdown voltage greaterthan about 10 volts, the solar cells grouped into one or more supercells each of which comprises two or more of the solar cells arranged inline with long sides of adjacent solar cells overlapping andconductively bonded to each other with an electrically and thermallyconductive adhesive;

wherein no single solar cell or group of <N solar cells in the string ofsolar cells is individually electrically connected in parallel with abypass diode.

2. The solar module of clause 1, wherein N is greater than or equal to30.

3. The solar module of clause 1, wherein N is greater than or equal to50.

4. The solar module of clause 1, wherein N is greater than or equal to100.

5. The solar module of clause 1, wherein the adhesive forms bondsbetween adjacent solar cells having a thickness perpendicular to thesolar cells less than or equal to about 0.1 mm and a thermalconductivity perpendicular to the solar cells greater than or equal toabout 1.5 w/m/k.

6. The solar module of clause 1, wherein the N solar cells are groupedinto a single super cell.

7. The solar module of clause 1, wherein the super cells areencapsulated in a polymer.

7A. The solar module of clause 7 wherein the polymer comprises athermoplastic olefin polymer.

7B. The solar module of clause 7 wherein the polymer is sandwichedbetween a glass front and back sheets.

7C. The solar module of clause 7B wherein the back sheets compriseglass.

8. The solar module of clause 1, wherein the solar cells are siliconsolar cells.

9. A solar module comprising:

a super cell substantially spanning a full length or width of the solarmodule parallel to an edge of the solar module, the super cellcomprising a series connected string of N rectangular or substantiallyrectangular solar cells having on average a breakdown voltage greaterthan about 10 volts arranged in line with long sides of adjacent solarcells overlapping and conductively bonded to each other with anelectrically and thermally conductive adhesive;

wherein no single solar cell or group of <N solar cells in the supercell is individually electrically connected in parallel with a bypassdiode.

10. The solar module of clause 9, wherein N>24.

11. The solar module of clause 9, wherein the super cell has a length inthe direction of current flow of at least about 500 mm.

12. The solar module of clause 9, wherein the super cells areencapsulated in a thermoplastic olefin polymer sandwiched between glassfront and back sheets.

13. A super cell comprising:

a plurality of silicon solar cells each comprising:

-   -   rectangular or substantially rectangular front and back surfaces        with shapes defined by first and second oppositely positioned        parallel long sides and two oppositely positioned short sides,        at least portions of the front surfaces to be exposed to solar        radiation during operation of the string of solar cells;    -   an electrically conductive front surface metallization pattern        disposed on the front surface and comprising at least one front        surface contact pad positioned adjacent to the first long side;        and    -   an electrically conductive back surface metallization pattern        disposed on the back surface and comprising at least one back        surface contact pad positioned adjacent the second long side;

wherein the silicon solar cells are arranged in line with first andsecond long sides of adjacent silicon solar cells overlapping and withfront surface and back surface contact pads on adjacent silicon solarcells overlapping and conductively bonded to each other with aconductive adhesive bonding material to electrically connect the siliconsolar cells in series; and

wherein the front surface metallization pattern of each silicon solarcell comprises a barrier configured to substantially confine theconductive adhesive bonding material to at least one front surfacecontact pad prior to curing of the conductive adhesive bonding materialduring manufacturing of the super cell.

14. The super cell of clause 13, wherein for each pair of adjacent andoverlapping silicon solar cells, the barrier on the front surface of oneof the silicon solar cells is overlapped and hidden by a portion of theother silicon solar cell, thereby substantially confining the conductiveadhesive bonding material to overlapped regions of the front surface ofthe silicon solar cell prior to curing of the conductive adhesivebonding material during manufacturing of the super cell.

15. The super cell of clause 13, wherein the barrier comprises acontinuous conductive line running parallel to and for substantially thefull length of the first long side, with at least one front surfacecontact pad located between the continuous conductive line and the firstlong side of the solar cell.

16. The super cell of clause 15, wherein the front surface metallizationpattern comprises fingers electrically connected to the at least onefront surface contact pads and running perpendicularly to the first longside, and the continuous conductive line electrically interconnects thefingers to provide multiple conductive paths from each finger to atleast one front surface contact pad.

17. The super cell of clause 13, wherein the front surface metallizationpattern comprises a plurality of discrete contact pads arranged in a rowadjacent to and parallel to the first long side, and the barriercomprises a plurality of features forming separate barriers for eachdiscrete contact pad that substantially confine the conductive adhesivebonding material to the discrete contact pads prior to curing of theconductive adhesive bonding material during manufacturing of the supercell.

18. The super cell of clause 17, wherein the separate barriers abut andare taller than their corresponding discrete contact pads.

19. A super cell comprising:

a plurality of silicon solar cells each comprising:

-   -   rectangular or substantially rectangular front and back surfaces        with shapes defined by first and second oppositely positioned        parallel long sides and two oppositely positioned short sides,        at least portions of the front surfaces to be exposed to solar        radiation during operation of the string of solar cells;    -   an electrically conductive front surface metallization pattern        disposed on the front surface and comprising at least one front        surface contact pad positioned adjacent to the first long side;        and    -   an electrically conductive back surface metallization pattern        disposed on the back surface and comprising at least one back        surface contact pad positioned adjacent the second long side;

wherein the silicon solar cells are arranged in line with first andsecond long sides of adjacent silicon solar cells overlapping and withfront surface and back surface contact pads on adjacent silicon solarcells overlapping and conductively bonded to each other with aconductive adhesive bonding material to electrically connect the siliconsolar cells in series; and

wherein the back surface metallization pattern of each silicon solarcell comprises a barrier configured to substantially confine theconducive adhesive bonding material to the at least one back surfacecontact pads prior to curing of the conductive adhesive bonding materialduring manufacturing of the super cell.

20. The super cell of clause 19, wherein the back surface metallizationpattern comprises one or more discrete contact pads arranged in a rowadjacent to and parallel to the second long side, and the barriercomprises a plurality of features forming separate barriers for eachdiscrete contact pad that substantially confine the conductive adhesivebonding material to the discrete contact pads prior to curing of theconductive adhesive bonding material during manufacturing of the supercell.

21. The super cell of clause 20, wherein the separate barriers abut andare taller than their corresponding discrete contact pads.

22. A method of making a string of solar cells, the method comprising:

dicing one or more pseudo square silicon wafers along a plurality oflines parallel to a long edge of each wafer to form a plurality ofrectangular silicon solar cells each having substantially the samelength along its long axis; and

arranging the rectangular silicon solar cells in line with long sides ofadjacent solar cells overlapping and conductively bonded to each otherto electrically connect the solar cells in series;

wherein the plurality of rectangular silicon solar cells comprises atleast one rectangular solar cell having two chamfered cornerscorresponding to corners or to portions of corners of the pseudo squarewafer, and one or more rectangular silicon solar cells each lackingchamfered corners; and

wherein the spacing between parallel lines along which the pseudo squarewafer is diced is selected to compensate for the chamfered corners bymaking the width perpendicular to the long axis of the rectangularsilicon solar cells that comprise chamfered corners greater than thewidth perpendicular to the long axis of the rectangular silicon solarcells that lack chamfered corners, so that each of the plurality ofrectangular silicon solar cells in the string of solar cells has a frontsurface of substantially the same area exposed to light in operation ofthe string of solar cells.

23. A string of solar cells comprising:

a plurality of silicon solar cells arranged in line with end portions ofadjacent solar cells overlapping and conductively bonded to each otherto electrically connect the solar cells in series;

wherein at least one of the silicon solar cells has chamfered cornersthat correspond to corners or portions of corners of a pseudo squaresilicon wafer from which it was diced, at least one of the silicon solarcells lacks chamfered corners, and each of the silicon solar cells has afront surface of substantially the same area exposed to light duringoperation of the string of solar cells.

24. A method of making two or more strings of solar cells, the methodcomprising:

dicing one or more pseudo square silicon wafers along a plurality oflines parallel to a long edge of each wafer to form a first plurality ofrectangular silicon solar cells comprising chamfered cornerscorresponding to corners or portions of corners of the pseudo squaresilicon wafers and a second plurality of rectangular silicon solar cellseach of a first length spanning a full width of the pseudo squaresilicon wafers and lacking chamfered corners;

removing the chamfered corners from each of the first plurality ofrectangular silicon solar cells to form a third plurality of rectangularsilicon solar cells each of a second length shorter than the firstlength and lacking chamfered corners;

arranging the second plurality of rectangular silicon solar cells inline with long sides of adjacent rectangular silicon solar cellsoverlapping and conductively bonded to each other to electricallyconnect the second plurality of rectangular silicon solar cells inseries to form a solar cell string having a width equal to the firstlength; and

arranging the third plurality of rectangular silicon solar cells in linewith long sides of adjacent rectangular silicon solar cells overlappingand conductively bonded to each other to electrically connect the thirdplurality of rectangular silicon solar cells in series to form a solarcell string having a width equal to the second length.

25. A method of making two or more strings of solar cells, the methodcomprising:

dicing one or more pseudo square silicon wafers along a plurality oflines parallel to a long edge of each wafer to form a first plurality ofrectangular silicon solar cells comprising chamfered cornerscorresponding to corners or portions of corners of the pseudo squaresilicon wafers and a second plurality of rectangular silicon solar cellslacking chamfered corners;

arranging the first plurality of rectangular silicon solar cells in linewith long sides of adjacent rectangular silicon solar cells overlappingand conductively bonded to each other to electrically connect the firstplurality of rectangular silicon solar cells in series; and

arranging the second plurality of rectangular silicon solar cells inline with long sides of adjacent rectangular silicon solar cellsoverlapping and conductively bonded to each other to electricallyconnect the second plurality of rectangular silicon solar cells inseries.

26. A method of making a solar module, the method comprising:

dicing each of a plurality of pseudo square silicon wafers along aplurality of lines parallel to a long edge of the wafer to form from theplurality of pseudo square silicon wafers a plurality of rectangularsilicon solar cells comprising chamfered corners corresponding tocorners of the pseudo square silicon wafers and a plurality ofrectangular silicon solar cells lacking chamfered corners;

arranging at least some of the rectangular silicon solar cells lackingchamfered corners to form a first plurality of super cells each of whichcomprises only rectangular silicon solar cells lacking chamfered cornersarranged in line with long sides of the silicon solar cells overlappingand conductively bonded to each other to electrically connect thesilicon solar cells in series;

arranging at least some of the rectangular silicon solar cellscomprising chamfered corners to form a second plurality of super cellseach of which comprises only rectangular silicon solar cells comprisingchamfered corners arranged in line with long sides of the silicon solarcells overlapping and conductively bonded to each other to electricallyconnect the silicon solar cells in series; and

arranging the super cells in parallel rows of super cells ofsubstantially equal length to form a front surface of the solar module,with each row comprising only super cells from the first plurality ofsuper cells or only super cells from the second plurality of supercells.

27. The solar module of clause 26, wherein two of the rows of supercells adjacent to parallel opposite edges of the solar module compriseonly super cells from the second plurality of super cells, and all otherrows of super cells comprise only super cells from the first pluralityof super cells.

28. The solar module of clause 27, wherein the solar module comprises atotal of six rows of super cells.

29. A super cell comprising:

a plurality of silicon solar cells arranged in line in a first directionwith end portions of adjacent silicon solar cells overlapping andconductively bonded to each other to electrically connect the siliconsolar cells in series; and

an elongated flexible electrical interconnect with its long axisoriented parallel to a second direction perpendicular to the firstdirection, conductively bonded to a front or back surface of an end oneof the silicon solar cells at three or more discrete locations arrangedalong the second direction, running at least the full width of the endsolar cell in the second direction, having a conductor thickness lessthan or equal to about 100 microns measured perpendicularly to the frontor rear surface of the end silicon solar cell, providing a resistance tocurrent flow in the second direction of less than or equal to about0.012 Ohms, and configured to provide flexibility accommodatingdifferential expansion in the second direction between the end siliconsolar cell and the interconnect for a temperature range of about −40° C.to about 85° C.

30. The super cell of clause 29, wherein the flexible electricalinterconnect has a conductor thickness less than or equal to about 30microns measured perpendicularly to the front and rear surfaces of theend silicon solar cell.

31. The super cell of clause 29, wherein the flexible electricalinterconnect extends beyond the super cell in the second direction toprovide for electrical interconnection to at least a second super cellpositioned parallel to and adjacent the super cell in a solar module.

32. The super cell of clause 29, wherein the flexible electricalinterconnect extends beyond the super cell in the first direction toprovide for electrical interconnection to a second super cell positionedparallel to and in line with the super cell in a solar module.

33. A solar module comprising:

a plurality of super cells arranged in two or more parallel rowsspanning a width of the module to form a front surface of the module,each super cell comprising a plurality of silicon solar cells arrangedin line with end portions of adjacent silicon solar cells overlappingand conductively bonded to each other to electrically connect thesilicon solar cells in series;

wherein at least an end of a first super cell adjacent an edge of themodule in a first row is electrically connected to an end of a secondsuper cell adjacent the same edge of the module in a second row via aflexible electrical interconnect that is bonded to the front surface ofthe first super cell at a plurality of discrete locations with anelectrically conductive adhesive bonding material, runs parallel to theedge of the module, and at least a portion of which folds around the endof the first super cell and is hidden from view from the front of themodule.

34. The solar module of clause 33, wherein surfaces of the flexibleelectrical interconnect on the front surface of the module are coveredor colored to reduce visible contrast with the super cells.

35. The solar module of clause 33, wherein the two or more parallel rowsof super cells are arranged on a white back sheet to form a frontsurface of the solar module to be illuminated by solar radiation duringoperation of the solar module, the white back sheet comprises paralleldarkened stripes having locations and widths corresponding to locationsand widths of gaps between the parallel rows of super cells, and whiteportions of the back sheets are not visible through the gaps between therows.

36. A method of making a string of solar cells, the method comprising:

laser scribing one or more scribe lines on each of one or more siliconsolar cells to define a plurality of rectangular regions on the siliconsolar cells,

applying an electrically conductive adhesive bonding material to the oneor more scribed silicon solar cells at one or more locations adjacent along side of each rectangular region;

separating the silicon solar cells along the scribe lines to provide aplurality of rectangular silicon solar cells each comprising a portionof the electrically conductive adhesive bonding material disposed on itsfront surface adjacent a long side;

arranging the plurality of rectangular silicon solar cells in line withlong sides of adjacent rectangular silicon solar cells overlapping in ashingled manner with a portion of the electrically conductive adhesivebonding material disposed in between; and

curing the electrically conductive bonding material, thereby bondingadjacent overlapping rectangular silicon solar cells to each other andelectrically connecting them in series.

37. A method of making a string of solar cells, the method comprising:

laser scribing one or more scribe lines on each of one or more siliconsolar cells to define a plurality of rectangular regions on the siliconsolar cells, each solar cell comprising a top surface and an oppositelypositioned bottom surface;

applying an electrically conductive adhesive bonding material toportions of the top surfaces of the one or more silicon solar cells;

applying a vacuum between the bottom surfaces of the one or more siliconsolar cells and a curved supporting surface to flex the one or moresilicon solar cells against the curved supporting surface and therebycleave the one or more silicon solar cells along the scribe lines toprovide a plurality of rectangular silicon solar cells each comprising aportion of the electrically conductive adhesive bonding materialdisposed on its front surface adjacent a long side;

arranging the plurality of rectangular silicon solar cells in line withlong sides of adjacent rectangular silicon solar cells overlapping in ashingled manner with a portion of the electrically conductive adhesivebonding material disposed in between; and

curing the electrically conductive bonding material, thereby bondingadjacent overlapping rectangular silicon solar cells to each other andelectrically connecting them in series.

38. The method of clause 37, comprising applying the electricallyconductive adhesive bonding material to the one or more silicon solarcells, then laser scribing the one or more scribe lines on each of theone or more silicon solar cells.

39. The method of clause 37, comprising laser scribing the one or morescribe lines on each of the one or more silicon solar cells, thenapplying the electrically conductive adhesive bonding material to theone or more silicon solar cells.

40. A solar module comprising:

a plurality of super cells arranged in two or more parallel rows to forma front surface of the solar module, each super cell comprising aplurality of silicon solar cells arranged in line with end portions ofadjacent silicon solar cells overlapping and conductively bonded to eachother to electrically connect the silicon solar cells in series, eachsuper cell comprising a front surface end contact at one end of thesuper cell and a back surface end contact of opposite polarity at anopposite end of the super cell;

wherein a first row of super cells comprises a first super cell arrangedwith its front surface end contact adjacent and parallel to a first edgeof the solar module, and the solar module comprises a first flexibleelectrical interconnect that is elongated and runs parallel to the firstedge of the solar module, is conductively bonded to the front surfaceend contact of the first super cell, and occupies only a narrow portionof the front surface of the solar module adjacent to the first edge ofthe solar module and no wider than about 1 centimeter measuredperpendicularly to the first edge of the solar module.

41. The solar module of clause 40, wherein a portion of the firstflexible electrical interconnect extends around the end of the firstsuper cell nearest to the first edge of the solar module, and behind thefirst super cell.

42. The solar module of clause 40, wherein the first flexibleinterconnect comprises a thin ribbon portion conductively bonded to thefront surface end contact of the first super cell and a thicker portionrunning parallel to the first edge of the solar module.

43. The solar module of clause 40, wherein the first flexibleinterconnect comprises a thin ribbon portion conductively bonded to thefront surface end contact of the first super cell and a coiled ribbonportion running parallel to the first edge of the solar module.

44. The solar module of clause 40, wherein a second row of super cellscomprises a second super cell arranged with its front surface endcontact adjacent to and parallel to the first edge of the solar module,and the front surface end contact of the first super cell iselectrically connected to the front surface end contact of the secondsuper cell via the first flexible electrical interconnect.

45. The solar module of clause 40, wherein the back surface end contactof the first super cell is located adjacent to and parallel to a secondedge of the solar module opposite from the first edge of the solarmodule, comprising a second flexible electrical interconnect that iselongated and runs parallel to the second edge of the solar module, isconductively bonded to the back surface end contact of the first supercell, and lies entirely behind the super cells.

46. The solar module of clause 45, wherein:

a second row of super cells comprises a second super cell arranged withits front surface end contact adjacent to and parallel to the first edgeof the solar module and its back surface end contact located adjacent toand parallel to the second edge of the solar module;

the front surface end contact of the first super cell is electricallyconnected to the front surface end contact of the second super cell viathe first flexible electrical interconnect; and

the back surface end contact of the first super cell is electricallyconnected to the back surface end contact of the second super cell viathe second flexible electrical interconnect.

47. The solar module of clause 40, comprising:

a second super cell arranged in the first row of super cells in serieswith the first super cell and with its back surface end contact adjacenta second edge of the solar module opposite from the first edge of thesolar module; and

a second flexible electrical interconnect that is elongated and runsparallel to the second edge of the solar module, is conductively bondedto the back surface end contact of the first super cell, and liesentirely behind the super cells.

48. The solar module of clause 47, wherein:

a second row of super cells comprises a third super cell and a fourthsuper cell arranged in series with a front surface end contact of thethird super cell adjacent the first edge of the solar module and theback surface end contact of the fourth super cell adjacent the secondedge of the solar module; and

the front surface end contact of the first super cell is electricallyconnected to the front surface end contact of the third super cell viathe first flexible electrical interconnect and the back surface endcontact of the second super cell is electrically connected to the backsurface end contact of the fourth super cell via the second flexibleelectrical interconnect.

49. The solar module of clause 40, wherein the super cells are arrangedon a white back sheet that comprises parallel darkened stripes havinglocations and widths corresponding to locations and widths of gapsbetween the parallel rows of super cells, and white portions of the backsheets are not visible through the gaps between the rows.

50. The solar module of clause 40, wherein all portions of the firstflexible electrical interconnect located on the front surface of thesolar module are covered or colored to reduce visible contrast with thesuper cells.

51. The solar module of clause 40, wherein:

each silicon solar cell comprises:

-   -   rectangular or substantially rectangular front and back surfaces        with shapes defined by first and second oppositely positioned        parallel long sides and two oppositely positioned short sides,        at least portions of the front surfaces to be exposed to solar        radiation during operation of the string of solar cells;    -   an electrically conductive front surface metallization pattern        disposed on the front surface and comprising a plurality of        fingers running perpendicular to the long sides and a plurality        of discrete front surface contact pads positioned in a row        adjacent to the first long side, each front surface contact pad        electrically connected to at least one of the fingers; and    -   an electrically conductive back surface metallization pattern        disposed on the back surface and comprising a plurality of        discrete back surface contact pads positioned in a row adjacent        the second long side; and

within each super cell the silicon solar cells are arranged in line withfirst and second long sides of adjacent silicon solar cells overlappingand with corresponding discrete front surface contact pads and discreteback surface contact pads on adjacent silicon solar cells aligned,overlapping, and conductively bonded to each other with a conductiveadhesive bonding material to electrically connect the silicon solarcells in series.

52. The solar module of clause 51, wherein the front surfacemetallization pattern of each silicon solar cell comprises a pluralityof thin conductors electrically interconnecting adjacent discrete frontsurface contact pads, and each thin conductor is thinner than the widthof the discrete contact pads measured perpendicularly to the long sidesof the solar cells.

53. The solar module of clause 51, wherein the conductive adhesivebonding material is substantially confined to the locations of thediscrete front surface contact pads by features of the front surfacemetallization pattern that form one or more barriers adjacent to thediscrete front surface contact pads.

54. The solar module of clause 51, wherein the conductive adhesivebonding material is substantially confined to the locations of thediscrete back surface contact pads by features of the back surfacemetallization pattern that form one or more barriers adjacent to thediscrete back surface contact pad.

55. A method of making a solar module, the method comprising:

assembling a plurality of super cells, each super cell comprising aplurality of rectangular silicon solar cells arranged in line with endportions on long sides of adjacent rectangular silicon solar cellsoverlapping in a shingled manner;

curing an electrically conductive bonding material disposed between theoverlapping end portions of adjacent rectangular silicon solar cells byapplying heat and pressure to the super cells, thereby bonding adjacentoverlapping rectangular silicon solar cells to each other andelectrically connecting them in series;

arranging and interconnecting the super cells in a desired solar moduleconfiguration in a stack of layers comprising an encapsulant; and

applying heat and pressure to the stack of layers to form a laminatedstructure.

56. The method of clause 55, comprising curing or partially curing theelectrically conductive bonding material by applying heat and pressureto the super cells prior to applying heat and pressure to the stack oflayers to form the laminated structure, thereby forming cured orpartially cured super cells as an intermediate product before formingthe laminated structure.

57. The method of clause 56, wherein as each additional rectangularsilicon solar cell is added to a super cell during assembly of the supercell, the electrically conductive adhesive bonding material between thenewly added solar cell and its adjacent overlapping solar cell is curedor partially cured before another rectangular silicon solar cell isadded to the super cell.

58. The method of clause 56, comprising curing or partially curing allof the electrically conductive bonding material in a super cell in thesame step.

59. The method of clause 56, comprising:

partially curing the electrically conductive bonding material byapplying heat and pressure to the super cells prior to applying heat andpressure to the stack of layers to form a laminated structure, therebyforming partially cured super cells as an intermediate product beforeforming the laminated structure; and

completing curing of the electrically conductive bonding material whileapplying heat and pressure to the stack of layers to form the laminatedstructure.

60. The method of clause 55, comprising curing the electricallyconductive bonding material while applying heat and pressure to thestack of layers to form a laminated structure, without forming cured orpartially cured super cells as an intermediate product before formingthe laminated structure.

61. The method of clause 55, comprising dicing one or more silicon solarcells into rectangular shapes to provide the rectangular silicon solarcells.

62. The method of clause 61, comprising applying the electricallyconductive adhesive bonding material to the one or more silicon solarcells before dicing the one or more silicon solar cells to providerectangular silicon solar cells with pre-applied electrically conductiveadhesive bonding material.

63. The method of clause 62, comprising applying the electricallyconductive adhesive bonding material to the one or more silicon solarcells, then using a laser to scribe one or more lines on each of the oneor more silicon solar cells, then cleaving the one or more silicon solarcells along the scribed lines.

64. The method of clause 62, comprising using a laser to scribe one ormore lines on each of the one or more silicon solar cells, then applyingthe electrically conductive adhesive bonding material to the one or moresilicon solar cells, then cleaving the one or more silicon solar cellsalong the scribed lines.

65. The method of clause 62, wherein the electrically conductiveadhesive bonding material is applied to a top surface of each of the oneor more silicon solar cells and not to an oppositely positioned bottomsurface of each of the one or more silicon solar cells, comprisingapplying a vacuum between the bottom surfaces of the one or more siliconsolar cells and a curved supporting surface to flex the one or moresilicon solar cells against the curved supporting surface and therebycleave the one or more silicon solar cells along scribe lines.

66. The method of clause 61, comprising applying the electricallyconductive adhesive bonding material to the rectangular silicon solarcells after dicing the one or more silicon solar cells to provide therectangular silicon solar cells.

67. The method of clause 55, wherein the conductive adhesive bondingmaterial has a glass transition temperature of less than or equal toabout 0° C.

FIG. 26 shows a diagram of the rear (shaded) surface of a solar moduleillustrating an example electrical interconnection of the front (sunside) surface terminal electrical contacts of a shingled super cell to ajunction box on the rear side of the module. The front surface terminalcontacts of the shingled super cell may be located adjacent to an edgeof the module.

FIG. 27 shows a diagram of the rear (shaded) surface of a solar moduleillustrating an example electrical interconnection of two or moreshingled super cells in parallel, with the front (sun side) surfaceterminal electrical contacts of the super cells connected to each otherand to a junction box on the rear side of the module. The front surfaceterminal contacts of the shingled super cells may be located adjacent toan edge of the module.

FIG. 28 shows a diagram of the rear (shaded) surface of a solar moduleillustrating another example electrical interconnection of two or moreshingled super cells in parallel, with the front (sun side) surfaceterminal electrical contacts of the super cells connected to each otherand to a junction box on the rear side of the module. The front surfaceterminal contacts of the shingled super cells may be located adjacent toan edge of the module.

FIG. 29 shows fragmentary cross-sectional and perspective diagrams oftwo super cells illustrating the use of a flexible interconnectsandwiched between overlapping ends of adjacent super cells toelectrically connect the super cells in series and to provide anelectrical connection to a junction box. FIG. 29A shows an enlarged viewof an area of interest in FIG. 29.

FIG. 29 and FIG. 29A show the use of an example flexible interconnect2960 partially sandwiched between and electrically interconnecting theoverlapping ends of two super cells 100 to provide an electricalconnection to the front surface end contact of one of the super cellsand to the rear surface end contact of the other super cell, therebyinterconnecting the super cells in series. In the illustrated example,interconnect 2960 is hidden from view from the front of the solar moduleby the upper of the two overlapping solar cells. In another variation,the adjacent ends of the two super cells do not overlap and the portionof interconnect 2960 connected to the front surface end contact of oneof the two super cells may be visible from the front surface of thesolar module. Optionally, in such variations the portion of theinterconnect that is otherwise visible from the front of the module maybe covered or colored (e.g., darkened) to reduce visible contrastbetween the interconnect and the super cells, as perceived by a humanhaving normal color vision. Interconnect 2960 may extend parallel to theadjacent edges of the two super cells beyond the side edges of the supercells to electrically connect the pair of super cells in parallel with asimilarly arranged pair of super cells in an adjacent row.

A ribbon conductor 2970 may be conductively bonded to interconnect 2960as shown to electrically connect the adjacent ends of the two supercells to electrical components (e.g., bypass diodes and/or moduleterminals in a junction box) on the rear surface of the solar module. Inanother variation (not shown) a ribbon conductor 2970 may beelectrically connected to the rear surface contact of one of theoverlapping super cells away from their overlapping ends, instead ofbeing conductively bonded to an interconnect 2960. That configurationmay also provide a hidden tap to one or more bypass diodes or otherelectrical components on the rear surface of the solar module.

Interconnect 2960 may be die cut from a conducting sheet, for example,and may be optionally patterned to increase its mechanical complianceboth perpendicular to and parallel to the edges of the super cells toreduce or accommodate stress perpendicular and parallel to the edges ofthe super cells arising from mismatch between the CTE of theinterconnect and that of the super cells. Such patterning may include,for example, slits, slots (as shown), or holes. The mechanicalcompliance of the flexible interconnect, and its bonds to the supercells, should be sufficient for the interconnected super cells tosurvive stress arising from CTE mismatch during the lamination processdescribed in more detail below. The flexible interconnect may be bondedto the super cells with, for example, a mechanically compliantelectrically conductive bonding material as described above for use inbonding overlapped solar cells. Optionally, the electrically conductivebonding material may be located only at discrete positions along theedges of the super cells rather than in a continuous line extendingsubstantially the length of the edge of the super cells, to reduce oraccommodate stress parallel to the edge of the super cells arising frommismatch between the coefficient of thermal expansion of theelectrically conductive bonding material or the interconnect and that ofthe super cells. Interconnect 2960 may be cut from a thin copper sheet,for example.

1A. A solar module comprising:

a plurality of super cells arranged in two or more parallel rows to forma front surface of the solar module, each super cell comprising aplurality of silicon solar cells arranged in line with end portions ofadjacent silicon solar cells overlapping and conductively bonded to eachother to electrically connect the silicon solar cells in series, eachsuper cell comprising a front surface end contact at one end of thesuper cell and a back surface end contact of opposite polarity at anopposite end of the super cell;

wherein a first row of super cells comprises a first super cell arrangedwith its front surface end contact adjacent and parallel to a first edgeof the solar module, and the solar module comprises a first flexibleelectrical interconnect that is elongated and runs parallel to the firstedge of the solar module, is conductively bonded to the front surfaceend contact of the first super cell, and occupies only a narrow portionof the front surface of the solar module adjacent to the first edge ofthe solar module and no wider than about 1 centimeter measuredperpendicularly to the first edge of the solar module.

2A. The solar module of clause 1A, wherein a portion of the firstflexible electrical interconnect extends around the end of the firstsuper cell nearest to the first edge of the solar module, and behind thefirst super cell.

3A. The solar module of clause 1A, wherein the first flexibleinterconnect comprises a thin ribbon portion conductively bonded to thefront surface end contact of the first super cell and a thicker portionrunning parallel to the first edge of the solar module.

4A. The solar module of clause 1A, wherein the first flexibleinterconnect comprises a thin ribbon portion conductively bonded to thefront surface end contact of the first super cell and a coiled ribbonportion running parallel to the first edge of the solar module.

5A. The solar module of clause 1A, wherein a second row of super cellscomprises a second super cell arranged with its front surface endcontact adjacent to and parallel to the first edge of the solar module,and the front surface end contact of the first super cell iselectrically connected to the front surface end contact of the secondsuper cell via the first flexible electrical interconnect.

6A. The solar module of clause 1A, wherein the back surface end contactof the first super cell is located adjacent to and parallel to a secondedge of the solar module opposite from the first edge of the solarmodule, comprising a second flexible electrical interconnect that iselongated and runs parallel to the second edge of the solar module, isconductively bonded to the back surface end contact of the first supercell, and lies entirely behind the super cells.

7A. The solar module of clause 6A, wherein:

a second row of super cells comprises a second super cell arranged withits front surface end contact adjacent to and parallel to the first edgeof the solar module and its back surface end contact located adjacent toand parallel to the second edge of the solar module;

the front surface end contact of the first super cell is electricallyconnected to the front surface end contact of the second super cell viathe first flexible electrical interconnect; and

the back surface end contact of the first super cell is electricallyconnected to the back surface end contact of the second super cell viathe second flexible electrical interconnect.

8A. The solar module of clause 1A, comprising:

a second super cell arranged in the first row of super cells in serieswith the first super cell and with its back surface end contact adjacenta second edge of the solar module opposite from the first edge of thesolar module; and

a second flexible electrical interconnect that is elongated and runsparallel to the second edge of the solar module, is conductively bondedto the back surface end contact of the first super cell, and liesentirely behind the super cells.

9A. The solar module of clause 8A, wherein:

a second row of super cells comprises a third super cell and a fourthsuper cell arranged in series with a front surface end contact of thethird super cell adjacent the first edge of the solar module and theback surface end contact of the fourth super cell adjacent the secondedge of the solar module; and

the front surface end contact of the first super cell is electricallyconnected to the front surface end contact of the third super cell viathe first flexible electrical interconnect and the back surface endcontact of the second super cell is electrically connected to the backsurface end contact of the fourth super cell via the second flexibleelectrical interconnect.

10A. The solar module of clause 1A, wherein away from outer edges of thesolar module there are no electrical interconnections between the supercells that reduce the active area of the front surface of the module.

11A. The solar module of clause 1A wherein at least one pair of supercells is arranged in line in a row with the rear surface contact end ofone of the pair of super cells adjacent to the rear surface contact endof the other of the pair of super cells.

12A. The solar module of clause 1A wherein:

at least one pair of super cells is arranged in line in a row withadjacent ends of the two super cells having end contacts of oppositepolarity;

the adjacent ends of the pair of super cells overlap; and

the super cells in the pair of super cells are electrically connected inseries by a flexible interconnect that is sandwiched between theiroverlapping ends and that does not shade the front surface.

13A. The solar module of clause 1A, wherein the super cells are arrangedon a white backing sheet that comprises parallel darkened stripes havinglocations and widths corresponding to locations and widths of gapsbetween the parallel rows of super cells, and white portions of thebacking sheets are not visible through the gaps between the rows.

14A. The solar module of clause 1A, wherein all portions of the firstflexible electrical interconnect located on the front surface of thesolar module are covered or colored to reduce visible contrast with thesuper cells.

15A. The solar module of clause 1A, wherein:

each silicon solar cell comprises:

-   -   rectangular or substantially rectangular front and back surfaces        with shapes defined by first and second oppositely positioned        parallel long sides and two oppositely positioned short sides,        at least portions of the front surfaces to be exposed to solar        radiation during operation of the string of solar cells;    -   an electrically conductive front surface metallization pattern        disposed on the front surface and comprising a plurality of        fingers running perpendicular to the long sides and a plurality        of discrete front surface contact pads positioned in a row        adjacent to the first long side, each front surface contact pad        electrically connected to at least one of the fingers; and    -   an electrically conductive back surface metallization pattern        disposed on the back surface and comprising a plurality of        discrete back surface contact pads positioned in a row adjacent        the second long side; and        within each super cell the silicon solar cells are arranged in        line with first and second long sides of adjacent silicon solar        cells overlapping and with corresponding discrete front surface        contact pads and discrete back surface contact pads on adjacent        silicon solar cells aligned, overlapping, and conductively        bonded to each other with a conductive adhesive bonding material        to electrically connect the silicon solar cells in series.

16A. The solar module of clause 15A, wherein the front surfacemetallization pattern of each silicon solar cell comprises a pluralityof thin conductors electrically interconnecting adjacent discrete frontsurface contact pads, and each thin conductor is thinner than the widthof the discrete contact pads measured perpendicularly to the long sidesof the solar cells.

17A. The solar module of clause 15A, wherein the conductive adhesivebonding material is substantially confined to the locations of thediscrete front surface contact pads by features of the front surfacemetallization pattern that form barriers around each discrete frontsurface contact pad.

18A. The solar module of clause 15A, wherein the conductive adhesivebonding material is substantially confined to the locations of thediscrete back surface contact pads by features of the back surfacemetallization pattern that form barriers around each discrete backsurface contact pad.

19A. The solar module of clause 15A, wherein the discrete back surfacecontact pads are discrete silver back surface contact pads, and exceptfor the discrete silver back surface contact pads the back surfacemetallization pattern of each silicon solar cell does not comprise asilver contact at any location that underlies a portion of the frontsurface of the solar cell that is not overlapped by an adjacent siliconsolar cell.

20A. A solar module comprising:

a plurality of super cells, each super cell comprising a plurality ofsilicon solar cells arranged in line with end portions of adjacentsilicon solar cells overlapping and conductively bonded to each other toelectrically connect the silicon solar cells in series;

wherein each silicon solar cell comprises:

-   -   rectangular or substantially rectangular front and back surfaces        with shapes defined by first and second oppositely positioned        parallel long sides and two oppositely positioned short sides,        at least portions of the front surfaces to be exposed to solar        radiation during operation of the string of solar cells;    -   an electrically conductive front surface metallization pattern        disposed on the front surface and comprising a plurality of        fingers running perpendicular to the long sides and a plurality        of discrete front surface contact pads positioned in a row        adjacent to the first long side,

each front surface contact pad electrically connected to at least one ofthe fingers; and

-   -   an electrically conductive back surface metallization pattern        disposed on the back surface and comprising a plurality of        discrete back surface contact pads positioned in a row adjacent        the second long side;

wherein within each super cell the silicon solar cells are arranged inline with first and second long sides of adjacent silicon solar cellsoverlapping and with corresponding discrete front surface contact padsand discrete back surface contact pads on adjacent silicon solar cellsaligned, overlapping, and conductively bonded to each other with aconductive adhesive bonding material to electrically connect the siliconsolar cells in series; and

wherein the super cells are arranged in a single row or in two or moreparallel rows substantially spanning a length or width of the solarmodule to form a front surface of the solar module to be illuminated bysolar radiation during operation of the solar module.

21A. The solar module of clause 20A, wherein the discrete back surfacecontact pads are discrete silver back surface contact pads, and exceptfor the discrete silver back surface contact pads the back surfacemetallization pattern of each silicon solar cell does not comprise asilver contact at any location that underlies a portion of the frontsurface of the solar cell that is not overlapped by an adjacent siliconsolar cell.

22A. The solar module of clause 20A, wherein the front surfacemetallization pattern of each silicon solar cell comprises a pluralityof thin conductors electrically interconnecting adjacent discrete frontsurface contact pads, and each thin conductor is thinner than the widthof the discrete contact pads measured perpendicularly to the long sidesof the solar cells.

23A. The solar module of clause 20A, wherein the conductive adhesivebonding material is substantially confined to the locations of thediscrete front surface contact pads by features of the front surfacemetallization pattern that form barriers around each discrete frontsurface contact pad.

24A. The solar module of clause 20A, wherein the conductive adhesivebonding material is substantially confined to the locations of thediscrete back surface contact pads by features of the back surfacemetallization pattern that form barriers around each discrete backsurface contact pad.

25A. A super cell comprising:

a plurality of silicon solar cells each comprising:

-   -   rectangular or substantially rectangular front and back surfaces        with shapes defined by first and second oppositely positioned        parallel long sides and two oppositely positioned short sides,        at least portions of the front surfaces to be exposed to solar        radiation during operation of the string of solar cells;    -   an electrically conductive front surface metallization pattern        disposed on the front surface and comprising a plurality of        fingers running perpendicular to the long sides and a plurality        of discrete front surface contact pads positioned in a row        adjacent to the first long side, each front surface contact pad        electrically connected to at least one of the fingers; and    -   an electrically conductive back surface metallization pattern        disposed on the back surface and comprising a plurality of        discrete silver back surface contact pads positioned in a row        adjacent the second long side;

wherein the silicon solar cells are arranged in line with first andsecond long sides of adjacent silicon solar cells overlapping and withcorresponding discrete front surface contact pads and discrete backsurface contact pads on adjacent silicon solar cells aligned,overlapping, and conductively bonded to each other with a conductiveadhesive bonding material to electrically connect the silicon solarcells in series.

26A. The solar module of clause 25A, wherein the discrete back surfacecontact pads are discrete silver back surface contact pads, and exceptfor the discrete silver back surface contact pads the back surfacemetallization pattern of each silicon solar cell does not comprise asilver contact at any location that underlies a portion of the frontsurface of the solar cell that is not overlapped by an adjacent siliconsolar cell.

27A. The string of solar cells of clause 25A, wherein the front surfacemetallization pattern comprises a plurality of thin conductorselectrically interconnecting adjacent discrete front surface contactpads, and each thin conductor is thinner than the width of the discretecontact pads measured perpendicularly to the long sides of the solarcells.

28A. The string of solar cells of clause 25A, wherein the conductiveadhesive bonding material is substantially confined to the locations ofthe discrete front surface contact pads by features of the front surfacemetallization pattern that form barriers around each discrete frontsurface contact pad.

29A. The string of solar cells of clause 25A, wherein the conductiveadhesive bonding material is substantially confined to the locations ofthe discrete back surface contact pads by features of the back surfacemetallization pattern that form barriers around each discrete backsurface contact pad.

30A. The string of solar cells of clause 25A, wherein the conductiveadhesive bonding material has a glass transition less than or equal toabout 0° C.

31. A method of making a solar module, the method comprising:

assembling a plurality of super cells, each super cell comprising aplurality of rectangular silicon solar cells arranged in line with endportions on long sides of adjacent rectangular silicon solar cellsoverlapping in a shingled manner;

curing an electrically conductive bonding material disposed between theoverlapping end portions of adjacent rectangular silicon solar cells byapplying heat and pressure to the super cells, thereby bonding adjacentoverlapping rectangular silicon solar cells to each other andelectrically connecting them in series;

arranging and interconnecting the super cells in a desired solar moduleconfiguration in a stack of layers comprising an encapsulant; and

applying heat and pressure to the stack of layers to form a laminatedstructure.

32A. The method of clause 31A, comprising curing or partially curing theelectrically conductive bonding material by applying heat and pressureto the super cells prior to applying heat and pressure to the stack oflayers to form the laminated structure, thereby forming cured orpartially cured super cells as an intermediate product before formingthe laminated structure.

33A. The method of clause 32A, wherein as each additional rectangularsilicon solar cell is added to a super cell during assembly of the supercell, the electrically conductive adhesive bonding material between thenewly added solar cell and its adjacent overlapping solar cell is curedor partially cured before another rectangular silicon solar cell isadded to the super cell.

34A. The method of clause 32A, comprising curing or partially curing allof the electrically conductive bonding material in a super cell in thesame step.

35A. The method of clause 32A, comprising:

partially curing the electrically conductive bonding material byapplying heat and pressure to the super cells prior to applying heat andpressure to the stack of layers to form a laminated structure, therebyforming partially cured super cells as an intermediate product beforeforming the laminated structure; and

completing curing of the electrically conductive bonding material whileapplying heat and pressure to the stack of layers to form the laminatedstructure.

36A. The method of clause 31A, comprising curing the electricallyconductive bonding material while applying heat and pressure to thestack of layers to form a laminated structure, without forming cured orpartially cured super cells as an intermediate product before formingthe laminated structure.

37A. The method of clause 31A, comprising dicing one or more siliconsolar cells into rectangular shapes to provide the rectangular siliconsolar cells.

38A. The method of clause 37A, comprising applying the electricallyconductive adhesive bonding material to the one or more silicon solarcells before dicing the one or more silicon solar cells to providerectangular silicon solar cells with pre-applied electrically conductiveadhesive bonding material.

39A. The method of clause 38A, comprising applying the electricallyconductive adhesive bonding material to the one or more silicon solarcells, then using a laser to scribe one or more lines on each of the oneor more silicon solar cells, then cleaving the one or more silicon solarcells along the scribed lines.

40A. The method of clause 38A, comprising using a laser to scribe one ormore lines on each of the one or more silicon solar cells, then applyingthe electrically conductive adhesive bonding material to the one or moresilicon solar cells, then cleaving the one or more silicon solar cellsalong the scribed lines.

41A. The method of clause 38A, wherein the electrically conductiveadhesive bonding material is applied to a top surface of each of the oneor more silicon solar cells and not to an oppositely positioned bottomsurface of each of the one or more silicon solar cells, comprisingapplying a vacuum between the bottom surfaces of the one or more siliconsolar cells and a curved supporting surface to flex the one or moresilicon solar cells against the curved supporting surface and therebycleave the one or more silicon solar cells along scribe lines.

42A. The method of clause 37A, comprising applying the electricallyconductive adhesive bonding material to the rectangular silicon solarcells after dicing the one or more silicon solar cells to provide therectangular silicon solar cells.

43A. The method of clause 31A, wherein the conductive adhesive bondingmaterial has a glass transition temperature of less than or equal toabout 0° C.

44A. A method of making a super cell, the method comprising:

laser scribing one or more scribe lines on each of one or more siliconsolar cells to define a plurality of rectangular regions on the siliconsolar cells, applying an electrically conductive adhesive bondingmaterial to the one or more scribed silicon solar cells at one or morelocations adjacent a long side of each rectangular region;

separating the silicon solar cells along the scribe lines to provide aplurality of rectangular silicon solar cells each comprising a portionof the electrically conductive adhesive bonding material disposed on itsfront surface adjacent a long side;

arranging the plurality of rectangular silicon solar cells in line withlong sides of adjacent rectangular silicon solar cells overlapping in ashingled manner with a portion of the electrically conductive adhesivebonding material disposed in between; and

curing the electrically conductive bonding material, thereby bondingadjacent overlapping rectangular silicon solar cells to each other andelectrically connecting them in series.

45A. A method of making a super cell, the method comprising:

laser scribing one or more scribe lines on each of one or more siliconsolar cells to define a plurality of rectangular regions on the siliconsolar cells, each solar cell comprising a top surface and an oppositelypositioned bottom surface;

applying an electrically conductive adhesive bonding material toportions of the top surfaces of the one or more silicon solar cells;

applying a vacuum between the bottom surfaces of the one or more siliconsolar cells and a curved supporting surface to flex the one or moresilicon solar cells against the curved supporting surface and therebycleave the one or more silicon solar cells along the scribe lines toprovide a plurality of rectangular silicon solar cells each comprising aportion of the electrically conductive adhesive bonding materialdisposed on its front surface adjacent a long side;

arranging the plurality of rectangular silicon solar cells in line withlong sides of adjacent rectangular silicon solar cells overlapping in ashingled manner with a portion of the electrically conductive adhesivebonding material disposed in between; and

curing the electrically conductive bonding material, thereby bondingadjacent overlapping rectangular silicon solar cells to each other andelectrically connecting them in series.

46A. A method of making a super cell, the method comprising:

dicing one or more pseudo square silicon wafers along a plurality oflines parallel to a long edge of each wafer to form a plurality ofrectangular silicon solar cells each having substantially the samelength along its long axis; and

arranging the rectangular silicon solar cells in line with long sides ofadjacent solar cells overlapping and conductively bonded to each otherto electrically connect the solar cells in series;

wherein the plurality of rectangular silicon solar cells comprises atleast one rectangular solar cell having two chamfered comerscorresponding to comers or to portions of comers of the pseudo squarewafer, and one or more rectangular silicon solar cells each lackingchamfered comers; and

wherein the spacing between parallel lines along which the pseudo squarewafer is diced is selected to compensate for the chamfered comers bymaking the width perpendicular to the long axis of the rectangularsilicon solar cells that comprise chamfered comers greater than thewidth perpendicular to the long axis of the rectangular silicon solarcells that lack chamfered comers, so that each of the plurality ofrectangular silicon solar cells in the string of solar cells has a frontsurface of substantially the same area exposed to light in operation ofthe string of solar cells.

47A. A super cell comprising:

a plurality of silicon solar cells arranged in line with end portions ofadjacent solar cells overlapping and conductively bonded to each otherto electrically connect the solar cells in series;

wherein at least one of the silicon solar cells has chamfered comersthat correspond to comers or portions of comers of a pseudo squaresilicon wafer from which it was diced, at least one of the silicon solarcells lacks chamfered comers, and each of the silicon solar cells has afront surface of substantially the same area exposed to light duringoperation of the string of solar cells.

48A. A method of making two or more super cells, the method comprising:

dicing one or more pseudo square silicon wafers along a plurality oflines parallel to a long edge of each wafer to form a first plurality ofrectangular silicon solar cells comprising chamfered comerscorresponding to comers or portions of comers of the pseudo squaresilicon wafers and a second plurality of rectangular silicon solar cellseach of a first length spanning a full width of the pseudo squaresilicon wafers and lacking chamfered comers;

removing the chamfered comers from each of the first plurality ofrectangular silicon solar cells to form a third plurality of rectangularsilicon solar cells each of a second length shorter than the firstlength and lacking chamfered comers;

arranging the second plurality of rectangular silicon solar cells inline with long sides of adjacent rectangular silicon solar cellsoverlapping and conductively bonded to each other to electricallyconnect the second plurality of rectangular silicon solar cells inseries to form a solar cell string having a width equal to the firstlength; and

arranging the third plurality of rectangular silicon solar cells in linewith long sides of adjacent rectangular silicon solar cells overlappingand conductively bonded to each other to electrically connect the thirdplurality of rectangular silicon solar cells in series to form a solarcell string having a width equal to the second length.

49A. A method of making two or more super cells, the method comprising:

dicing one or more pseudo square silicon wafers along a plurality oflines parallel to a long edge of each wafer to form a first plurality ofrectangular silicon solar cells comprising chamfered comerscorresponding to comers or portions of comers of the pseudo squaresilicon wafers and a second plurality of rectangular silicon solar cellslacking chamfered comers;

arranging the first plurality of rectangular silicon solar cells in linewith long sides of adjacent rectangular silicon solar cells overlappingand conductively bonded to each other to electrically connect the firstplurality of rectangular silicon solar cells in series; and

arranging the second plurality of rectangular silicon solar cells inline with long sides of adjacent rectangular silicon solar cellsoverlapping and conductively bonded to each other to electricallyconnect the second plurality of rectangular silicon solar cells inseries.

50A. A solar module comprising:

a series connected string of N≧than 25 rectangular or substantiallyrectangular solar cells having on average a breakdown voltage greaterthan about 10 volts, the solar cells grouped into one or more supercells each of which comprises two or more of the solar cells arranged inline with long sides of adjacent solar cells overlapping andconductively bonded to each other with an electrically and thermallyconductive adhesive;

wherein no single solar cell or group of <N solar cells in the string ofsolar cells is individually electrically connected in parallel with abypass diode.

51A. The solar module of clause 50A, wherein N is greater than or equalto 30.

52A. The solar module of clause 50A, wherein N is greater than or equalto 50.

53A. The solar module of clause 50A, wherein N is greater than or equalto 100.

54A. The solar module of clause 50A, wherein the adhesive forms bondsbetween adjacent solar cells having a thickness perpendicular to thesolar cells less than or equal to about 0.1 mm and a thermalconductivity perpendicular to the solar cells greater than or equal toabout 1.5 w/m/k.

55A. The solar module of clause 50A, wherein the N solar cells aregrouped into a single super cell.

56A. The solar module of clause 50A, wherein the solar cells are siliconsolar cells.

57A. A solar module comprising:

a super cell substantially spanning a full length or width of the solarmodule parallel to an edge of the solar module, the super cellcomprising a series connected string of N rectangular or substantiallyrectangular solar cells having on average a breakdown voltage greaterthan about 10 volts arranged in line with long sides of adjacent solarcells overlapping and conductively bonded to each other with anelectrically and thermally conductive adhesive;

wherein no single solar cell or group of <N solar cells in the supercell is individually electrically connected in parallel with a bypassdiode.

58A. The solar module of clause 57A, wherein N>24.

59A. The solar module of clause 57A, wherein the super cell has a lengthin the direction of current flow of at least about 500 mm.

60. A super cell comprising:

a plurality of silicon solar cells each comprising:

-   -   rectangular or substantially rectangular front and back surfaces        with shapes defined by first and second oppositely positioned        parallel long sides and two oppositely positioned short sides,        at least portions of the front surfaces to be exposed to solar        radiation during operation of the string of solar cells;    -   an electrically conductive front surface metallization pattern        disposed on the front surface and comprising at least one front        surface contact pad positioned adjacent to the first long side;        and    -   an electrically conductive back surface metallization pattern        disposed on the back surface and comprising at least one back        surface contact pad positioned adjacent the second long side;

wherein the silicon solar cells are arranged in line with first andsecond long sides of adjacent silicon solar cells overlapping and withfront surface and back surface contact pads on adjacent silicon solarcells overlapping and conductively bonded to each other with aconductive adhesive bonding material to electrically connect the siliconsolar cells in series; and

wherein the front surface metallization pattern of each silicon solarcell comprises a barrier configured to substantially confine theconducive adhesive bonding material to the at least one front surfacecontact pads prior to curing of the conductive adhesive bonding materialduring manufacturing of the super cell.

61A. The super cell of clause 60A, wherein for each pair of adjacent andoverlapping silicon solar cells, the barrier on the front surface of oneof the silicon solar cells is overlapped and hidden by a portion of theother silicon solar cell, thereby substantially confining the conductiveadhesive bonding material to overlapped regions of the front surface ofthe silicon solar cell prior to curing of the conductive adhesivebonding material during manufacturing of the super cell.

62A. The super cell of clause 60A, wherein the barrier comprises acontinuous conductive line running parallel to and for substantially thefull length of the first long side, with the at least one front surfacecontact pads located between the continuous conductive line and thefirst long side of the solar cell.

63A. The super cell of clause 62A, wherein the front surfacemetallization pattern comprises fingers electrically connected to the atleast one front surface contact pads and running perpendicularly to thefirst long side, and the continuous conductive line electricallyinterconnects the fingers to provide multiple conductive paths from eachfinger to the at least one front surface contact pads.

64A. The super cell of clause 60A, wherein the front surfacemetallization pattern comprises a plurality of discrete contact padsarranged in a row adjacent to and parallel to the first long side, andthe barrier comprises a plurality of features forming separate barriersfor each discrete contact pad that substantially confine the conductiveadhesive bonding material to the discrete contact pads prior to curingof the conductive adhesive bonding material during manufacturing of thesuper cell.

65A. The super cell of clause 64A, wherein the separate barriers abutand are taller than their corresponding discrete contact pads.

66A. A super cell comprising:

a plurality of silicon solar cells each comprising:

-   -   rectangular or substantially rectangular front and back surfaces        with shapes defined by first and second oppositely positioned        parallel long sides and two oppositely positioned short sides,        at least portions of the front surfaces to be exposed to solar        radiation during operation of the string of solar cells;    -   an electrically conductive front surface metallization pattern        disposed on the front surface and comprising at least one front        surface contact pad positioned adjacent to the first long side;        and    -   an electrically conductive back surface metallization pattern        disposed on the back surface and comprising at least one back        surface contact pad positioned adjacent the second long side;

wherein the silicon solar cells are arranged in line with first andsecond long sides of adjacent silicon solar cells overlapping and withfront surface and back surface contact pads on adjacent silicon solarcells overlapping and conductively bonded to each other with aconductive adhesive bonding material to electrically connect the siliconsolar cells in series; and

wherein the back surface metallization pattern of each silicon solarcell comprises a barrier configured to substantially confine theconducive adhesive bonding material to the at least one back surfacecontact pads prior to curing of the conductive adhesive bonding materialduring manufacturing of the super cell.

67A. The super cell of clause 66A, wherein the back surfacemetallization pattern comprises one or more discrete contact padsarranged in a row adjacent to and parallel to the second long side, andthe barrier comprises a plurality of features forming separate barriersfor each discrete contact pad that substantially confine the conductiveadhesive bonding material to the discrete contact pads prior to curingof the conductive adhesive bonding material during manufacturing of thesuper cell.

68A. The super cell of clause 67A, wherein the separate barriers abutand are taller than their corresponding discrete contact pads.

69A. A method of making a string of solar cells, the method comprising:

dicing one or more pseudo square silicon wafers along a plurality oflines parallel to a long edge of each wafer to form a plurality ofrectangular silicon solar cells each having substantially the samelength along its long axis; and

arranging the rectangular silicon solar cells in line with long sides ofadjacent solar cells overlapping and conductively bonded to each otherto electrically connect the solar cells in series;

wherein the plurality of rectangular silicon solar cells comprises atleast one rectangular solar cell having two chamfered comerscorresponding to comers or to portions of comers of the pseudo squarewafer, and one or more rectangular silicon solar cells each lackingchamfered comers; and

wherein the spacing between parallel lines along which the pseudo squarewafer is diced is selected to compensate for the chamfered comers bymaking the width perpendicular to the long axis of the rectangularsilicon solar cells that comprise chamfered comers greater than thewidth perpendicular to the long axis of the rectangular silicon solarcells that lack chamfered comers, so that each of the plurality ofrectangular silicon solar cells in the string of solar cells has a frontsurface of substantially the same area exposed to light in operation ofthe string of solar cells.

70A. A string of solar cells comprising:

a plurality of silicon solar cells arranged in line with end portions ofadjacent solar cells overlapping and conductively bonded to each otherto electrically connect the solar cells in series;

wherein at least one of the silicon solar cells has chamfered comersthat correspond to comers or portions of comers of a pseudo squaresilicon wafer from which it was diced, at least one of the silicon solarcells lacks chamfered comers, and each of the silicon solar cells has afront surface of substantially the same area exposed to light duringoperation of the string of solar cells.

71A. A method of making two or more strings of solar cells, the methodcomprising:

dicing one or more pseudo square silicon wafers along a plurality oflines parallel to a long edge of each wafer to form a first plurality ofrectangular silicon solar cells comprising chamfered comerscorresponding to comers or portions of comers of the pseudo squaresilicon wafers and a second plurality of rectangular silicon solar cellseach of a first length spanning a full width of the pseudo squaresilicon wafers and lacking chamfered comers;

removing the chamfered comers from each of the first plurality ofrectangular silicon solar cells to form a third plurality of rectangularsilicon solar cells each of a second length shorter than the firstlength and lacking chamfered comers;

arranging the second plurality of rectangular silicon solar cells inline with long sides of adjacent rectangular silicon solar cellsoverlapping and conductively bonded to each other to electricallyconnect the second plurality of rectangular silicon solar cells inseries to form a solar cell string having a width equal to the firstlength; and

arranging the third plurality of rectangular silicon solar cells in linewith long sides of adjacent rectangular silicon solar cells overlappingand conductively bonded to each other to electrically connect the thirdplurality of rectangular silicon solar cells in series to form a solarcell string having a width equal to the second length.

72A. A method of making two or more strings of solar cells, the methodcomprising:

dicing one or more pseudo square silicon wafers along a plurality oflines parallel to a long edge of each wafer to form a first plurality ofrectangular silicon solar cells comprising chamfered comerscorresponding to comers or portions of comers of the pseudo squaresilicon wafers and a second plurality of rectangular silicon solar cellslacking chamfered comers;

arranging the first plurality of rectangular silicon solar cells in linewith long sides of adjacent rectangular silicon solar cells overlappingand conductively bonded to each other to electrically connect the firstplurality of rectangular silicon solar cells in series; and

arranging the second plurality of rectangular silicon solar cells inline with long sides of adjacent rectangular silicon solar cellsoverlapping and conductively bonded to each other to electricallyconnect the second plurality of rectangular silicon solar cells inseries.

73A. A method of making a solar module, the method comprising:

dicing each of a plurality of pseudo square silicon wafers along aplurality of lines parallel to a long edge of the wafer to form from theplurality of pseudo square silicon wafers a plurality of rectangularsilicon solar cells comprising chamfered comers corresponding to comersof the pseudo square silicon wafers and a plurality of rectangularsilicon solar cells lacking chamfered comers;

arranging at least some of the rectangular silicon solar cells lackingchamfered comers to form a first plurality of super cells each of whichcomprises only rectangular silicon solar cells lacking chamfered comersarranged in line with long sides of the silicon solar cells overlappingand conductively bonded to each other to electrically connect thesilicon solar cells in series;

arranging at least some of the rectangular silicon solar cellscomprising chamfered comers to form a second plurality of super cellseach of which comprises only rectangular silicon solar cells comprisingchamfered comers arranged in line with long sides of the silicon solarcells overlapping and conductively bonded to each other to electricallyconnect the silicon solar cells in series; and

arranging the super cells in parallel rows of super cells ofsubstantially equal length to form a front surface of the solar module,with each row comprising only super cells from the first plurality ofsuper cells or only super cells from the second plurality of supercells.

74A. The solar module of clause 73A, wherein two of the rows of supercells adjacent to parallel opposite edges of the solar module compriseonly super cells from the second plurality of super cells, and all otherrows of super cells comprise only super cells from the first pluralityof super cells.

75A. The solar module of clause 74A, wherein the solar module comprisesa total of six rows of super cells.

76A. A super cell comprising:

a plurality of silicon solar cells arranged in line in a first directionwith end portions of adjacent silicon solar cells overlapping andconductively bonded to each other to electrically connect the siliconsolar cells in series; and

an elongated flexible electrical interconnect with its long axisoriented parallel to a second direction perpendicular to the firstdirection, conductively bonded to a front or back surface of an end oneof the silicon solar cells at three or more discrete locations arrangedalong the second direction, running at least the full width of the endsolar cell in the second direction, having a conductor thickness lessthan or equal to about 100 microns measured perpendicularly to the frontor rear surface of the end silicon solar cell, providing a resistance tocurrent flow in the second direction of less than or equal to about0.012 Ohms, and configured to provide flexibility accommodatingdifferential expansion in the second direction between the end siliconsolar cell and the interconnect for a temperature range of about −40° C.to about 85° C.

77A. The super cell of clause 76A, wherein the flexible electricalinterconnect has a conductor thickness less than or equal to about 30microns measured perpendicularly to the front and rear surfaces of theend silicon solar cell.

78A. The super cell of clause 76A, wherein the flexible electricalinterconnect extends beyond the super cell in the second direction toprovide for electrical interconnection to at least a second super cellpositioned parallel to and adjacent the super cell in a solar module.

79A. The super cell of clause 76A, wherein the flexible electricalinterconnect extends beyond the super cell in the first direction toprovide for electrical interconnection to a second super cell positionedparallel to and in line with the super cell in a solar module.

80A. A solar module comprising:

a plurality of super cells arranged in two or more parallel rowsspanning a width of the module to form a front surface of the module,each super cell comprising a plurality of silicon solar cells arrangedin line with end portions of adjacent silicon solar cells overlappingand conductively bonded to each other to electrically connect thesilicon solar cells in series;

wherein at least an end of a first super cell adjacent an edge of themodule in a first row is electrically connected to an end of a secondsuper cell adjacent the same edge of the module in a second row via aflexible electrical interconnect that is bonded to the front surface ofthe first super cell at a plurality of discrete locations with anelectrically conductive adhesive bonding material, runs parallel to theedge of the module, and at least a portion of which folds around the endof the first super cell and is hidden from view from the front of themodule.

81A. The solar module of clause 80A, wherein surfaces of the flexibleelectrical interconnect on the front surface of the module are coveredor colored to reduce visible contrast with the super cells.

82A. The solar module of clause 80A, wherein the two or more parallelrows of super cells are arranged on a white backing sheet to form afront surface of the solar module to be illuminated by solar radiationduring operation of the solar module, the white backing sheet comprisesparallel darkened stripes having locations and widths corresponding tolocations and widths of gaps between the parallel rows of super cells,and white portions of the backing sheets are not visible through thegaps between the rows.

83A. A method of making a string of solar cells, the method comprising:

laser scribing one or more scribe lines on each of one or more siliconsolar cells to define a plurality of rectangular regions on the siliconsolar cells,

applying an electrically conductive adhesive bonding material to the oneor more scribed silicon solar cells at one or more locations adjacent along side of each rectangular region; separating the silicon solar cellsalong the scribe lines to provide a plurality of rectangular siliconsolar cells each comprising a portion of the electrically conductiveadhesive bonding material disposed on its front surface adjacent a longside;

arranging the plurality of rectangular silicon solar cells in line withlong sides of adjacent rectangular silicon solar cells overlapping in ashingled manner with a portion of the electrically conductive adhesivebonding material disposed in between; and

curing the electrically conductive bonding material, thereby bondingadjacent overlapping rectangular silicon solar cells to each other andelectrically connecting them in series.

84A. A method of making a string of solar cells, the method comprising:

laser scribing one or more scribe lines on each of one or more siliconsolar cells to define a plurality of rectangular regions on the siliconsolar cells, each solar cell comprising a top surface and an oppositelypositioned bottom surface;

applying an electrically conductive adhesive bonding material toportions of the top surfaces of the one or more silicon solar cells;

applying a vacuum between the bottom surfaces of the one or more siliconsolar cells and a curved supporting surface to flex the one or moresilicon solar cells against the curved supporting surface and therebycleave the one or more silicon solar cells along the scribe lines toprovide a plurality of rectangular silicon solar cells each comprising aportion of the electrically conductive adhesive bonding materialdisposed on its front surface adjacent a long side;

arranging the plurality of rectangular silicon solar cells in line withlong sides of adjacent rectangular silicon solar cells overlapping in ashingled manner with a portion of the electrically conductive adhesivebonding material disposed in between; and

curing the electrically conductive bonding material, thereby bondingadjacent overlapping rectangular silicon solar cells to each other andelectrically connecting them in series.

85A. The method of clause 84A, comprising applying the electricallyconductive adhesive bonding material to the one or more silicon solarcells, then laser scribing the one or more scribe lines on each of theone or more silicon solar cells.

86A. The method of clause 84A, comprising laser scribing the one or morescribe lines on each of the one or more silicon solar cells, thenapplying the electrically conductive adhesive bonding material to theone or more silicon solar cells.

Embodiments may include one or more features described in the followingU.S. Patent Publication documents: U.S. Patent Publication No.2014/0124013; and U.S. Patent Publication No. 2014/0124014, both ofwhich are incorporated by reference in their entireties herein for allpurposes.

This disclosure is illustrative and not limiting. Further modificationswill be apparent to one skilled in the art in light of this disclosureand are intended to fall within the scope of the appended claims.

What is claimed is:
 1. An apparatus comprising: a solar modulecomprising a front surface including a first series connected string ofsilicon solar cells grouped into a first super cell comprising a firstsilicon solar cell having chamfered corners and arranged with a sideoverlapping and conductively bonded with an adhesive to a second siliconsolar cell.
 2. An apparatus as in claim 1 wherein the second siliconsolar cell lacks chamfered corners, each silicon solar cell of the firstsuper cell having substantially a same front surface area exposed tolight.
 3. An apparatus as in claim 2 wherein: the first silicon solarcell and the second silicon solar cell have a same length; and a widthof the first silicon solar cell is greater than a width of the secondsilicon solar cell.
 4. An apparatus as in claim 3 wherein the lengthreproduces a shape of a pseudo-square wafer.
 5. An apparatus as in claim3 wherein the length is 156 mm.
 6. An apparatus as in claim 3 whereinthe length is 125 mm.
 7. An apparatus as in claim 3 wherein an aspectratio between the width and the length of the first solar cell isbetween about 1:2 to about 1:20.
 8. An apparatus as in claim 3 whereinthe first silicon solar cell overlaps the second silicon solar cell bybetween about 1 mm to about 5 mm.
 9. An apparatus as in claim 3 whereinthe first super cell comprises at least nineteen silicon solar cellseach having a breakdown voltage greater than about 10 volts.
 10. Anapparatus as in claim 3 wherein the first super cell has a length in adirection of current flow of at least about 500 mm.
 11. An apparatus asin claim 3 wherein: the first super cell is connected in parallel with asecond super cell on the front surface; and the front surface comprisesa white backing featuring darkened stripes of location and widthcorresponding to gaps between the first super cell and the second supercell.
 12. An apparatus as in claim 1 wherein the second silicon solarcell includes chamfered corners.
 13. An apparatus as in claim 12 whereina long side of the first silicon solar cell overlaps a long side of thesecond silicon solar cell.
 14. An apparatus as in claim 12 wherein along side of the first silicon solar cell overlaps a short side of thesecond silicon solar cell.
 15. An apparatus as in claim 1 wherein thefront surface comprises: a first row comprising the first super cellconsisting of solar cells with chamfered corners; and a second rowcomprising a second series connected string of silicon solar cellsgrouped into a second super cell connected in parallel with the firstsuper cell and consisting of solar cells lacking chamfered corners, alength of the second row substantially a same as a length of the firstrow.
 16. An apparatus as in claim 15 wherein the first row is adjacentto a module edge and the second row is not adjacent to the module edge.17. An apparatus as in claim 15 wherein the first super cell comprisesat least nineteen solar cells each having a breakdown voltage greaterthan about 10 volts, and the first super cell has a length in adirection of current flow of at least about 500 mm.
 18. An apparatus asin claim 15 wherein the front surface comprises a white backingfeaturing darkened stripes of location and width corresponding to gapsbetween the first super cell and the second super cell.
 19. An apparatusas in claim 1 further comprising a metallization pattern on a front sideof the second solar cell.
 20. An apparatus as in claim 19 wherein themetallization pattern comprises a tapered portion extending around achamfered corner.
 21. An apparatus as in claim 19 wherein themetallization pattern comprises a raised feature to confine spreading ofthe adhesive.
 22. An apparatus as in claim 19 wherein the metallizationpattern comprises: a plurality of discrete contact pads; fingerselectrically connected to the a plurality of discrete contact pads; anda conductive line interconnecting the fingers.
 23. An apparatus as inclaim 22 wherein the metallization pattern forms a plurality of separatebarriers to confine the adhesive to the discrete contact pads.
 24. Anapparatus as in claim 23 wherein the plurality of separate barriers abutand are taller than corresponding discrete contact pads.
 25. Anapparatus as in claim 1 further comprising a flexible electricalinterconnect conductively bonded to a surface of the first solar celland accommodating thermal expansion of the first solar cell in twodimensions.
 26. An apparatus as in claim 25 wherein a first portion ofthe interconnect folds around an edge of the first super cell such thata remaining second interconnect portion is on a backside of the firstsuper cell.
 27. An apparatus as in claim 1 wherein the module has a topconductive ribbon on the front surface facing a direction of solarenergy, the apparatus further comprising: another module having a secondsuper cell disposed on a front surface, a bottom ribbon on the othermodule facing away from the solar energy, and wherein the second moduleoverlaps and is bonded to a portion of the first module including thetop ribbon.
 28. An apparatus as in claim 27 wherein the other module isbonded to the module by adhesive.
 29. An apparatus as in claim 27further comprising a junction box overlapped by the other module.
 30. Anapparatus as in claim 29 wherein the other module is bonded to themodule by a mating arrangement between the junction box and anotherjunction box on the other module.
 31. An apparatus as in claim 29wherein the junction box houses a single module terminal.
 32. Anapparatus as in claim 27 further comprising a switch between the moduleand the other module.
 33. An apparatus as in claim 32 further comprisinga voltage sensing controller in communication with the switch.
 34. Anapparatus as in claim 27 wherein the first super cell comprises notfewer than nineteen solar cells electrically connected with a singlebypass diode.
 35. An apparatus as in claim 34 wherein the single bypassdiode is positioned near a first module edge.
 36. An apparatus as inclaim 34 wherein the single bypass diode is positioned in a laminatestructure.
 37. An apparatus as in claim 36 wherein the super cell isencapsulated within the laminate structure.
 38. An apparatus as in claim34 wherein the single bypass diode is positioned around a first moduleperimeter.
 39. An apparatus as in claim 27 wherein the first super celland the second super cell comprise a pair connected to a powermanagement device.
 40. An apparatus as in claim 27 further comprising apower management device configured to, receive a voltage output of thefirst super cell; based upon the voltage, determine if a solar cell ofthe first super cell is in reverse bias; and disconnect the solar cellin reverse bias from a super cell module circuit.